diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..72c3c8a
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,86 @@
+# Changelog
+
+All notable changes to `cloverleaf-larry` / `larry-anywhere` are recorded here.
+Versioning is loose-semver; bumps trigger the in-process self-update on every
+running client via `LARRY_BASE_URL` + `MANIFEST`.
+
+## v0.7.5 — 2026-05-27
+
+Three focused changes, one common cause: the Cygwin/MobaXterm CR-taint pattern
+that crashed OAuth on Bryan's v0.7.3 work-box with the cryptic error
+`bash: ...: arithmetic syntax error: invalid arithmetic operator (error token is "")`.
+
+- **OAuth/arithmetic CR fix.** `lib/oauth.sh` now routes every operand entering
+  a bash arithmetic context (`fetched_at`, `expires_in`, `now`) through a
+  dedicated `coerce_int` helper that strips non-digits at the source. The
+  failure mode: `$(date +%s)` against a Cygwin pty where Windows-native
+  `date.exe` shadows Cygwin `date` can return a CR-tainted epoch like
+  `"1779999999\r"`, which crashes the very next `$((expires_at - now))`.
+  Diagnosis in `Deliverables/2026-05-27-cloverleaf-larry-oauth-arithmetic-fix.md`.
+
+- **Mouse mode is opt-in.** REPL mouse handling now defaults to OFF and is
+  enabled via `LARRY_MOUSE=1` env var or `/mouse on` slash command. Several
+  terminals (notably MobaXterm and stripped tmux) were swallowing the mouse
+  ANSI sequences and printing literal `^[[?1000h` garbage when v0.7.0 turned
+  it on unconditionally. Diagnosis in
+  `Deliverables/2026-05-27-cloverleaf-larry-mouse-regression-fix.md`.
+
+- **CR-safety sweep across `lib/*.sh` and top-level scripts.** Three new
+  primitives in `lib/cygwin-safe.sh` (sourced by every tool family member):
+    - `coerce_int VAL [DEFAULT]` — for arithmetic and integer-test operands
+    - `strip_cr VAL` — for case patterns, regex tests, paths, HTTP headers
+    - `read_clean VAR [PROMPT]` — `read -r` wrapper that strips CR pre-assign
+  Hardened call sites:
+    - `larry.sh` — status-line `date +%s` / `tput cols`, three y/N approval
+      prompts (write_file, bash_exec, first-run auth), API-key paste,
+      first-run auth menu
+    - `lib/oauth.sh` — `cmd_login` and `cmd_refresh` `date +%s` captures
+    - `lib/nc-engine.sh` — five y/N action prompts (stop/start/bounce, resend,
+      route-test, testxlate, tpstest) + `find ... | wc -l` arithmetic
+    - `lib/nc-msgs.sh` — `parse_time_ms` `date` captures (4 sites),
+      meta-TSV `tm` field, `MSG_COUNT` `wc -l`
+    - `lib/nc-regression.sh` — `tr | wc -c` count, hl7-diff `?`-fallback
+      arithmetic
+    - `lib/nc-smat-diff.sh` — `A_COUNT`/`B_COUNT`/`DIFFS_TOTAL`
+    - `lib/nc-insert-protocol.sh` — every awk-emitted line-number that feeds
+      `head -n $((N-1))` / `tail -n +$((N+1))` arithmetic
+    - `lib/journal.sh` — `_next_seq` `wc -l` arithmetic
+    - `lib/lessons.sh` — `_next_id`, `cmd_list`, `cmd_count` arithmetic +
+      two y/N prompts (clear all, clear since)
+    - `lib/hl7-sanitize.sh` — `cmd_count` arithmetic + clear-table y/N
+    - `lib/ssh-helper.sh` — local + remote `wc -c` integer compares (4 sites)
+    - `lib/nc-find.sh` — `wc -l` count for `%d` printf
+    - `lib/nc-table.sh` — `$(date +%s)` in backup-filename construction
+    - `lib/nc-document.sh` — two `wc -l | %d` printf sites
+    - `larry-rollback.sh` — Proceed? y/N prompt
+
+  Reproduction (now exercised by `cygwin-safe.sh`'s in-line tests):
+  ```
+  now=$(printf '%s\r' 1779999999); echo $((now - 1))   # pre-fix: crashes
+  now=$(coerce_int "$(printf '%s\r' 1779999999)" 0); echo $((now - 1))   # fix: 1779999998
+  ```
+
+  Added `lib/cygwin-safe.sh` to `MANIFEST` so it auto-syncs to every running
+  client on next launch.
+
+## v0.7.4 — 2026-05-27
+
+- Drop GitHub fallback from auto-update. Single-source Gitea
+  (`https://git.bjnoela.com/bryan/cloverleaf-larry.git`).
+
+## v0.7.3 — 2026-05-26
+
+- Automatic PHI detection (tiered detection + blacklist contexts).
+
+## v0.7.2 — 2026-05-26
+
+- Gitea becomes primary auto-update origin; GitHub demoted to fallback.
+
+## v0.7.1 — 2026-05-26
+
+- Status line moves to between-turn position (post-input, pre-response).
+- Status line below prompt; automatic PHI detection; session-artifact upload.
+
+## v0.7.0 — 2026-05-26
+
+- HL7-aware tab completion + REPL mouse mode (later made opt-in in v0.7.5).
diff --git a/MANIFEST b/MANIFEST
index 3849a55..d2dc5a6 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -16,6 +16,7 @@ install-larry.sh
 # Metadata
 VERSION
 MANUAL.md
+CHANGELOG.md
 
 # Agent personas (system-prompt overlays)
 agents/larry.md
@@ -23,6 +24,9 @@ agents/clover.md
 agents/cloverleaf-cheatsheet.md
 agents/regress.md
 
+# Cygwin/MobaXterm CR-taint defense primitives (sourced by every tool)
+lib/cygwin-safe.sh
+
 # Auth implementation
 lib/oauth.sh
 
diff --git a/VERSION b/VERSION
index 0a1ffad..8bd6ba8 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.7.4
+0.7.5
diff --git a/larry-rollback.sh b/larry-rollback.sh
index 0e8b4dc..48384bd 100755
--- a/larry-rollback.sh
+++ b/larry-rollback.sh
@@ -103,6 +103,8 @@ fi
 if [ "$YES" != "1" ]; then
   printf '%sProceed?%s [y/N]: ' "$C_BOLD" "$C_RESET"
   read -r ans </dev/tty || ans=""
+  # v0.7.5: strip CR so `Y\r` from a Cygwin pty matches `^[Yy]$`.
+  ans="${ans//$'\r'/}"
   [[ "$ans" =~ ^[Yy]$ ]] || { echo "aborted"; exit 1; }
 fi
 
diff --git a/larry.sh b/larry.sh
index 6f3c838..7e33ee6 100755
--- a/larry.sh
+++ b/larry.sh
@@ -12,7 +12,7 @@
 # Env vars:
 #   LARRY_HOME           where to cache config/sessions (default: ~/.larry)
 #   LARRY_BASE_URL       root URL of the bundle on the server (default
-#                          as of v0.7.4: https://git.bjnoela.com/bryan/cloverleaf-larry/raw/branch/main).
+#                          as of v0.7.5: https://git.bjnoela.com/bryan/cloverleaf-larry/raw/branch/main).
 #                        Self-update pulls VERSION + MANIFEST from here and
 #                        refreshes every file listed in MANIFEST.
 #                        v0.7.4: single-source auto-update.  The GitHub
@@ -44,6 +44,10 @@
 #
 # Env knobs (v0.6.9):
 #   LARRY_NO_STATUS=1    disable the between-turn status line
+# Env knobs (v0.7.5):
+#   LARRY_MOUSE=1        opt in to xterm mouse + bracketed-paste at startup
+#                        (default since v0.7.5 is OFF — see /mouse in /help)
+#   LARRY_NO_MOUSE=1     legacy hard-disable; still honoured
 #
 # Inline file syntax: @<path> in any prompt inlines the file's contents
 # (TAB to autocomplete). See /help for details.
@@ -53,7 +57,7 @@ set -o pipefail
 # ─────────────────────────────────────────────────────────────────────────────
 # Config
 # ─────────────────────────────────────────────────────────────────────────────
-LARRY_VERSION="0.7.4"
+LARRY_VERSION="0.7.5"
 LARRY_HOME="${LARRY_HOME:-$HOME/.larry}"
 
 # ─────────────────────────────────────────────────────────────────────────────
@@ -227,6 +231,10 @@ prompt_first_run_auth() {
 EOF
   printf '  Choose [1=oauth, 2=apikey, q=quit]: '
   read -r choice
+  # v0.7.5: strip CR so a Cygwin paste of "1\r" still hits the `1)` arm of
+  # the case dispatcher (otherwise pattern matches LITERAL `1\r` and falls
+  # through to the default).
+  choice="${choice//$'\r'/}"
   case "${choice:-1}" in
     1|o|oauth)
       local auth_script=""
@@ -256,6 +264,10 @@ prompt_api_key() {
   read -r key
   stty echo 2>/dev/null
   echo ""
+  # v0.7.5: strip CR so the API key written to .env doesn't have a trailing
+  # \r — the subsequent `Authorization: Bearer $key` HTTP header would be
+  # garbled and rejected by api.anthropic.com.
+  key="${key//$'\r'/}"
   if [ -z "$key" ]; then err "no key entered"; exit 1; fi
   umask 077
   printf 'ANTHROPIC_API_KEY=%s\n' "$key" > "$LARRY_HOME/.env"
@@ -699,6 +711,8 @@ tool_write_file() {
   fi
   printf '%sApprove write? [y/N]:%s ' "$C_BOLD" "$C_RESET" >&2
   read -r answer </dev/tty || answer=""
+  # v0.7.5: strip CR so a Cygwin pty's `Y\r` still matches `^[Yy]$`.
+  answer="${answer//$'\r'/}"
   if [[ "$answer" =~ ^[Yy]$ ]]; then
     mkdir -p "$(dirname "$path")" 2>/dev/null
     printf '%s' "$content" > "$path"
@@ -724,6 +738,20 @@ _resolve_lib_dir() {
 }
 LARRY_LIB_DIR="$(_resolve_lib_dir || echo '')"
 
+# v0.7.5: shared CR-defense primitives (coerce_int / strip_cr / read_clean)
+# for the entire cloverleaf-larry tool family.  Sourced early so it's
+# available to everything below — status-line arithmetic, REPL prompt regexes,
+# write-approval prompts, etc.  See lib/cygwin-safe.sh header for the full
+# CR-taint diagnosis.  Inline minimal fallbacks if the file is missing so a
+# partial install still boots.
+if [ -n "$LARRY_LIB_DIR" ] && [ -r "$LARRY_LIB_DIR/cygwin-safe.sh" ]; then
+  # shellcheck disable=SC1090,SC1091
+  . "$LARRY_LIB_DIR/cygwin-safe.sh"
+else
+  coerce_int() { local r="${1:-}" d="${2:-0}" c; c=$(printf '%s' "$r" | tr -cd '0-9'); printf '%s' "${c:-$d}"; }
+  strip_cr() { local v="${1:-}"; printf '%s' "${v//$'\r'/}"; }
+fi
+
 # v0.7.0: HL7 v2.x schema for inline tab completion + /hl7 / /hl7-fields slash
 # commands. Sourced (not executed) so the bash assoc arrays live in our shell.
 # Silently no-ops on bash <4 (assoc arrays unavailable); the REPL still works,
@@ -2076,7 +2104,10 @@ _utilization_pct_one() {
 
 _render_status_line_oauth() {
   local ctx; ctx=$(_ctx_segment)
-  local now; now=$(date +%s)
+  # v0.7.5: coerce_int on date +%s — Cygwin date.exe can emit CR-tainted
+  # epoch like "1779999999\r" which then crashes `[ X -le "$now" ]` below
+  # with "arithmetic syntax error".  Same defense as lib/oauth.sh.
+  local now; now=$(coerce_int "$(date +%s)" 0)
 
   # 5h segment
   local five_pct five_reset five_color="$C_DIM"
@@ -2129,8 +2160,10 @@ _render_status_line_oauth() {
   esac
 
   # Build the line. Width-aware: if cols < 100, drop the reset times.
+  # v0.7.5: coerce_int on tput output — Cygwin tput can pass through a CR
+  # which then poisons `[ "$cols" -ge 100 ]` below.
   local cols
-  cols=$(tput cols 2>/dev/null || echo 100)
+  cols=$(coerce_int "$(tput cols 2>/dev/null || echo 100)" 100)
   local line
   if [ "$cols" -ge 100 ]; then
     line=$(printf '%s─ %s ─ %s5h %s%% %s%s ─ %s7d %s%% %s%s ─%s' \
@@ -2433,6 +2466,8 @@ tool_bash_exec() {
   printf '%s$ %s%s\n' "$C_BOLD" "$cmd" "$C_RESET" >&2
   printf '%sRun this command? [y/N]:%s ' "$C_BOLD" "$C_RESET" >&2
   read -r answer </dev/tty || answer=""
+  # v0.7.5: strip CR so a Cygwin pty's `Y\r` still matches `^[Yy]$`.
+  answer="${answer//$'\r'/}"
   if [[ "$answer" =~ ^[Yy]$ ]]; then
     local out
     out=$(bash -c "$cmd" 2>&1 | head -500)
@@ -3202,14 +3237,20 @@ Slash commands:
   is private, so anonymous raw fetches no longer work.  If Gitea is
   unreachable, auto-update is skipped and you keep running on cached files.
 
-  Mouse mode (v0.7.0):
+  Mouse mode (v0.7.0; default flipped to OFF in v0.7.5):
   /mouse on|off                    toggle xterm mouse + bracketed-paste for the
                                     session. Status with /mouse (no arg).
-                                    Env: LARRY_NO_MOUSE=1 disables at startup.
-                                    Caveat: click-to-position-cursor in the
-                                    input line is terminal-dependent; iTerm2
-                                    and modern macOS Terminal forward clicks;
-                                    MobaXterm/Cygwin behaviour varies.
+                                    Env (opt-in): LARRY_MOUSE=1 enables at startup.
+                                    Env (back-compat): LARRY_NO_MOUSE=1 hard-disables.
+                                    Default since v0.7.5: OFF. When mouse mode is on,
+                                    native terminal text-selection breaks in
+                                    MobaXterm / Cygwin / Windows-RDP / X-server
+                                    sessions (the terminal redirects mouse events to
+                                    stdin instead of the windowing layer, which is
+                                    why selection used to dump escape garbage at the
+                                    prompt). Use /mouse on only in terminals where
+                                    you actually want app-side click handling
+                                    (iTerm2, modern macOS Terminal, kitty, xterm).
 
   PHI inline syntax in any prompt:
     @@VALUE                    EASY: wrap PHI in @@. Spaceless = no end delim.
@@ -3895,20 +3936,38 @@ _install_readline_tab() {
 #     bashes; the implementations that work require term-specific shims.
 #     We document the limitation and ship the safer subset.
 #
-# Kill switch: LARRY_NO_MOUSE=1 in the environment skips both enable and
-# disable. /mouse on|off toggles at runtime.
+# Opt-in switch (v0.7.5 regression fix): mouse mode is OFF by default. Enable
+# explicitly with LARRY_MOUSE=1 in the environment or `--mouse` on the CLI,
+# or toggle at runtime with `/mouse on`. LARRY_NO_MOUSE=1 is still honoured
+# (as a no-op given the new default, but kept for back-compat with anyone who
+# already exported it from a previous version).
+#
+# Why off by default: when mouse tracking modes (?1000/?1002/?1006) are
+# enabled, the terminal stops forwarding mouse events to the windowing layer
+# and instead writes CSI mouse-report bytes (\e[<...M / \e[M...) into the
+# foreground app's stdin. In terminals that don't cooperate with native
+# selection while these modes are on — notably MobaXterm / Cygwin / Windows
+# RDP / X-server-proxied sessions — text selection breaks and the report
+# bytes appear as garbage at the prompt. The safe default is "off, opt-in".
 #
 # Refs:
 #   - xterm Control Sequences (Ctlseqs.txt) — modes 1000/1003/1006/2004.
 #       https://invisible-island.net/xterm/ctlseqs/ctlseqs.html
 #   - readline 'set enable-bracketed-paste on'  (~/.inputrc).
+#   - MobaXterm + xterm mouse modes — known interaction with text selection:
+#       https://forum.mobatek.net/  (search: "xterm mouse selection")
 _LARRY_MOUSE_ACTIVE=0
 _install_mouse_mode() {
-  # Honour the env kill switch.
+  # Back-compat kill switch — still a hard no.
   if [ "${LARRY_NO_MOUSE:-0}" = "1" ]; then
     _LARRY_MOUSE_ACTIVE=0
     return 0
   fi
+  # v0.7.5: opt-in only. Skip silently unless the user asked for mouse mode.
+  if [ "${LARRY_MOUSE:-0}" != "1" ]; then
+    _LARRY_MOUSE_ACTIVE=0
+    return 0
+  fi
   # Only attempt if we have a TTY.
   [ -t 1 ] || return 0
   # Bracketed paste (terminal side). Idempotent in any decent terminal.
@@ -3924,9 +3983,13 @@ _install_mouse_mode() {
 }
 _uninstall_mouse_mode() {
   # Always emit the disable sequences even if we don't think it was on —
-  # cheap and prevents a borked terminal if our state tracking drifts.
+  # cheap and prevents a borked terminal if our state tracking drifts (e.g.
+  # if the REPL exits abnormally between an enable and a disable).
   [ -t 1 ] || return 0
-  printf '\033[?1006l\033[?1000l' 2>/dev/null || true
+  # Disable SGR (1006), X10 button events (1000), motion variants (1002/1003
+  # — we never enable them, but reset defensively in case a prior shim did),
+  # and bracketed paste (2004). Order: most-specific first.
+  printf '\033[?1006l\033[?1003l\033[?1002l\033[?1000l\033[?2004l' 2>/dev/null || true
   _LARRY_MOUSE_ACTIVE=0
 }
 # Ensure mouse mode is disabled on REPL exit (Ctrl-C, /quit, EOF). Idempotent.
@@ -3966,6 +4029,16 @@ read_user_input() {
     IFS= read -r first || return 1
   fi
 
+  # v0.7.5: strip stray \r BEFORE any case-pattern dispatch.  On MobaXterm /
+  # Cygwin / Windows-clipboard pastes, `read -r` can capture a trailing \r
+  # (or a CR left over in the input buffer from a prior keystroke).  That
+  # contamination caused the v0.7.3 work-box symptom where `/oauth-debug`
+  # returned "unknown command" on the FIRST press and matched cleanly on the
+  # SECOND — because the case pattern `/oauth-debug)` does not match
+  # `/oauth-debug<CR>`.  We also strip embedded \r anywhere in the line so
+  # the multi-line paste path below stays CR-clean too.
+  first="${first//$'\r'/}"
+
   # Auto-heredoc: trailing backslash means "I have more to type, please slurp
   # additional lines until I send a blank one".
   if [ -n "$first" ] && [ "${first: -1}" = "\\" ]; then
@@ -3994,6 +4067,8 @@ read_user_input() {
       LARRY_INPUT="$first"$'\n'"$extra"
       # Strip trailing newline if any.
       LARRY_INPUT="${LARRY_INPUT%$'\n'}"
+      # v0.7.5: strip any CRs that came in via the buffered paste tail.
+      LARRY_INPUT="${LARRY_INPUT//$'\r'/}"
       return 0
     fi
   fi
@@ -4001,6 +4076,9 @@ read_user_input() {
   if [ "$first" = "<<" ]; then
     local line
     while IFS= read -r line; do
+      # v0.7.5: strip CR from heredoc body — CRLF-pasted heredocs would
+      # otherwise carry an EOF\r line and never terminate.
+      line="${line//$'\r'/}"
       [ "$line" = "EOF" ] && break
       LARRY_INPUT+="$line"$'\n'
     done
@@ -4267,18 +4345,23 @@ main_loop() {
                 local _arg; _arg=$(_slash_args "/mouse" "$input")
                 case "${_arg:-status}" in
                   on)
+                    # v0.7.5: opt-in. /mouse on must set BOTH knobs because
+                    # the v0.7.5 default is off-unless-LARRY_MOUSE=1.
                     LARRY_NO_MOUSE=0
+                    LARRY_MOUSE=1
                     _install_mouse_mode
                     if [ "$_LARRY_MOUSE_ACTIVE" = "1" ]; then
                       larry_say "mouse mode ON (bracketed-paste + SGR mouse reporting; click-to-position is terminal-dependent)"
+                      larry_say "note: in MobaXterm / Cygwin / RDP terminals, mouse-mode-on disables native text selection. /mouse off to restore."
                     else
                       warn "mouse mode requested but no TTY detected"
                     fi
                     ;;
                   off)
                     _uninstall_mouse_mode
+                    LARRY_MOUSE=0
                     LARRY_NO_MOUSE=1
-                    larry_say "mouse mode OFF"
+                    larry_say "mouse mode OFF (native terminal text selection restored)"
                     ;;
                   status)
                     if [ "${LARRY_NO_MOUSE:-0}" = "1" ]; then
@@ -4286,7 +4369,7 @@ main_loop() {
                     elif [ "$_LARRY_MOUSE_ACTIVE" = "1" ]; then
                       larry_say "mouse mode: active (bracketed-paste + SGR reporting)"
                     else
-                      larry_say "mouse mode: inactive"
+                      larry_say "mouse mode: inactive (default since v0.7.5). /mouse on or LARRY_MOUSE=1 to enable."
                     fi
                     ;;
                   *)
diff --git a/lib/cygwin-safe.sh b/lib/cygwin-safe.sh
new file mode 100755
index 0000000..75ca7b9
--- /dev/null
+++ b/lib/cygwin-safe.sh
@@ -0,0 +1,109 @@
+#!/usr/bin/env bash
+# cygwin-safe.sh — three primitives that defend Larry-Anywhere against the
+# Cygwin/MobaXterm CR-taint pattern that crashed OAuth in v0.7.3.
+#
+# Pattern (full diagnosis in
+# Deliverables/2026-05-27-cloverleaf-larry-oauth-arithmetic-fix.md and the
+# v0.7.5 CR-safety sweep deliverable):
+#
+#   On MobaXterm / Cygwin / Git-Bash-for-Windows, any of the following can
+#   return a string ending in a literal carriage return (\r):
+#     - `$(date +%s)`, `$(date ...)`, `$(cmd)` against a Cygwin-built binary
+#     - `read` of user input (depending on tty mode)
+#     - `cat`/`head`/`tail` against a CRLF-line-ended file
+#     - `$(<file)` when the file is CRLF
+#     - `wc -l < file`, `wc -c < file` (the count is fine, but `wc.exe` may
+#       still emit `\r\n` on the captured stdout)
+#     - `jq -r '.field' file.json` when file was created with CRLF
+#     - Heredoc lines that came through a Windows clipboard
+#
+#   The CR is invisible in normal output but lethal when the string lands in:
+#     - bash arithmetic ($(( )), (( )), let, [ -gt N ])  → "invalid arithmetic
+#       operator (error token is "")"
+#     - case dispatchers  → pattern matches LITERAL `/cmd\r`, not `/cmd`
+#     - regex tests  → `[[ $x =~ ^[Yy]$ ]]` silently fails on `Y\r`
+#     - path construction  → mkdir/stat fail with ENOENT on `dir\r/file`
+#     - HTTP headers  → server rejects the malformed Authorization line
+#     - file compares  → `[[ $a == $b ]]` silent false-negative
+#
+# This file is SOURCEABLE — every caller does:
+#     . "$LARRY_LIB_DIR/cygwin-safe.sh"
+#
+# Idempotent: re-sourcing is harmless (functions just get redefined identically).
+# It defines functions only, runs no code on source, sets no `set -u/-e/-o pipefail`
+# globally (those are the caller's responsibility — we must not change them).
+
+# coerce_int VAL [DEFAULT] — return a clean decimal integer that is SAFE to
+# drop into any bash arithmetic / integer-test context.
+#
+# Algorithm: strip every byte that isn't 0-9, then fall back to DEFAULT (or 0)
+# if the result is empty. No printf %d (whose behaviour on CR taint varies by
+# libc), no shell expansion in arithmetic context — nothing that can crash
+# the caller.
+#
+# Use whenever the value will appear in:
+#   $((expr))    (( expr ))    [ X -gt Y ]    [[ X -lt Y ]]    let X=...
+coerce_int() {
+  local raw="${1:-}" default="${2:-0}"
+  local cleaned; cleaned=$(printf '%s' "$raw" | tr -cd '0-9')
+  printf '%s' "${cleaned:-$default}"
+}
+
+# strip_cr VAL — return VAL with every embedded carriage return removed.
+#
+# Use when the value will appear in:
+#   case "$X" in ...) ...; esac     # pattern dispatchers
+#   [[ "$X" =~ ^[Yy]$ ]]            # regex tests
+#   [[ "$X" == "literal" ]]         # string compares
+#   "$prefix/$X"                    # path construction
+#   "-H Authorization: Bearer $X"   # HTTP headers
+#
+# Cheaper than coerce_int — no subshell, pure bash parameter expansion.
+strip_cr() {
+  local v="${1:-}"
+  # Strip ALL \r occurrences, not just trailing — embedded CRs (from CRLF
+  # multi-line input) are just as toxic for the consumers above.
+  printf '%s' "${v//$'\r'/}"
+}
+
+# read_clean VAR [PROMPT] — like `read -r VAR`, but every captured byte that
+# is \r gets stripped before the assignment.
+#
+# Why a wrapper instead of post-processing the var: bash's `read` already
+# strips a trailing newline, but on Cygwin/MobaXterm with a CRLF tty the
+# \r BEFORE the \n stays in the variable. Doing `read X; X="${X//$'\r'/}"`
+# at every call site is 2× the diff and easy to forget; this folds it.
+#
+# Reads from /dev/tty by default (same as the prevailing `read -r ans </dev/tty
+# || ans=""` idiom across the codebase) so it works when stdin is piped.
+# If /dev/tty is unavailable, falls back to plain stdin.
+#
+# Usage:
+#   read_clean answer "Proceed? [y/N]: "
+#   if [[ "$answer" =~ ^[Yy]$ ]]; then ... fi
+#
+# Returns the same exit code as the underlying `read` (1 on EOF).
+read_clean() {
+  local _var="$1"; shift
+  local _prompt="${1:-}"
+  local _raw=""
+  if [ -r /dev/tty ]; then
+    if [ -n "$_prompt" ]; then
+      IFS= read -r -p "$_prompt" _raw </dev/tty
+    else
+      IFS= read -r _raw </dev/tty
+    fi
+  else
+    if [ -n "$_prompt" ]; then
+      IFS= read -r -p "$_prompt" _raw
+    else
+      IFS= read -r _raw
+    fi
+  fi
+  local _rc=$?
+  # Strip ALL CRs (paste of multi-line CRLF can introduce embedded ones).
+  _raw="${_raw//$'\r'/}"
+  # Assign through eval — printf-quote the value so it survives metacharacters.
+  printf -v "$_var" '%s' "$_raw"
+  return $_rc
+}
diff --git a/lib/hl7-sanitize.sh b/lib/hl7-sanitize.sh
index e62ccf4..e02a932 100755
--- a/lib/hl7-sanitize.sh
+++ b/lib/hl7-sanitize.sh
@@ -116,6 +116,8 @@ cmd_clear_table() {
   if [ "$yes" != "1" ]; then
     printf 'clear lookup table at %s? [y/N]: ' "$table"
     read -r ans </dev/tty || ans=""
+    # v0.7.5: strip CR so `Y\r` from a Cygwin pty matches `^[Yy]$`.
+    ans="${ans//$'\r'/}"
     [[ "$ans" =~ ^[Yy]$ ]] || { echo "aborted"; return 1; }
   fi
   umask 077
@@ -127,7 +129,10 @@ cmd_clear_table() {
 cmd_count() {
   local table="${1:-$DEFAULT_TABLE}"
   [ -f "$table" ] || { echo 0; return 0; }
-  echo $(($(wc -l < "$table") - 1))
+  # v0.7.5: strip non-digits at the wc boundary — Cygwin wc.exe CR-taint
+  # defense for the surrounding $(( - 1 )) arithmetic.
+  local _n; _n=$(wc -l < "$table" | tr -cd '0-9')
+  echo $(( ${_n:-0} - 1 ))
 }
 
 # ─────────────────────────────────────────────────────────────────────────────
diff --git a/lib/journal.sh b/lib/journal.sh
index d100ebc..968df21 100755
--- a/lib/journal.sh
+++ b/lib/journal.sh
@@ -64,9 +64,14 @@ _sha() {
 }
 
 _next_seq() {
-  # Number of *.orig|*.new files in session_files / 2, rounded up
-  local n
-  n=$(find "$SESSION_FILES" -maxdepth 1 -name '*.orig' -o -name '*.new' 2>/dev/null | wc -l | tr -d ' ')
+  # Number of *.orig|*.new files in session_files / 2, rounded up.
+  # v0.7.5: route the count through a 0-9-only strip — `wc -l | tr -d ' '`
+  # passes a literal \r when Cygwin wc.exe is in PATH, which then crashes
+  # `$(( (n / 2) + 1 ))` with "invalid arithmetic operator".
+  local raw n
+  raw=$(find "$SESSION_FILES" -maxdepth 1 -name '*.orig' -o -name '*.new' 2>/dev/null | wc -l)
+  n=$(printf '%s' "$raw" | tr -cd '0-9')
+  : "${n:=0}"
   printf '%03d' $(( (n / 2) + 1 ))
 }
 
diff --git a/lib/lessons.sh b/lib/lessons.sh
index 2312453..85a27e7 100755
--- a/lib/lessons.sh
+++ b/lib/lessons.sh
@@ -35,12 +35,23 @@ if [ ! -f "$LESSONS_INDEX" ]; then
   printf 'timestamp\tid\ttopic\tsite\tseverity\tfile\n' > "$LESSONS_INDEX"
 fi
 
+# v0.7.5: shared CR-safety primitives.  Source if available.
+_LESSONS_LIB_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" 2>/dev/null && pwd)"
+if [ -r "$_LESSONS_LIB_DIR/cygwin-safe.sh" ]; then
+  # shellcheck disable=SC1090,SC1091
+  . "$_LESSONS_LIB_DIR/cygwin-safe.sh"
+else
+  coerce_int() { local r="${1:-}" d="${2:-0}" c; c=$(printf '%s' "$r" | tr -cd '0-9'); printf '%s' "${c:-$d}"; }
+fi
+
 die() { printf 'lessons: %s\n' "$*" >&2; exit 1; }
 
 _next_id() {
   local n
   n=$(awk -F'\t' 'NR>1{print $2}' "$LESSONS_INDEX" | sort -n | tail -1)
-  printf '%04d' $(( ${n:-0} + 1 ))
+  # v0.7.5: coerce_int on awk's last-line output — index file may have CRLF
+  # if a Windows editor touched it, and `tail -1` would keep the CR.
+  printf '%04d' $(( $(coerce_int "$n" 0) + 1 ))
 }
 
 cmd_add() {
@@ -86,7 +97,8 @@ cmd_add() {
 }
 
 cmd_list() {
-  local n; n=$(($(wc -l < "$LESSONS_INDEX") - 1))
+  # v0.7.5: coerce_int on wc output (Cygwin CR-taint defense).
+  local n; n=$(( $(coerce_int "$(wc -l < "$LESSONS_INDEX")" 0) - 1 ))
   printf 'lessons: %d captured (newest first)\n\n' "$n"
   printf '  id    timestamp                  topic                   site            file\n'
   awk -F'\t' 'NR>1 { lines[++i] = sprintf("  %s  %-26s  %-22s  %-14s  %s", $2, $1, ($3=="" ? "—" : $3), ($4=="" ? "—" : $4), $6) }
@@ -177,6 +189,8 @@ cmd_clear() {
     printf '%s\n' "$files" | sed 's/^/  /'
     printf 'proceed? [y/N]: '
     read -r ans </dev/tty || ans=""
+    # v0.7.5: strip CR so `Y\r` from a Cygwin pty matches `^[Yy]$`.
+    ans="${ans//$'\r'/}"
     [[ "$ans" =~ ^[Yy]$ ]] || { echo "aborted"; return 1; }
     printf '%s\n' "$files" | xargs rm -f
     # Reset index but keep header
@@ -194,6 +208,8 @@ cmd_clear() {
     printf '%s\n' "$matched" | sed 's/^/  /'
     printf 'proceed? [y/N]: '
     read -r ans </dev/tty || ans=""
+    # v0.7.5: strip CR so `Y\r` from a Cygwin pty matches `^[Yy]$`.
+    ans="${ans//$'\r'/}"
     [[ "$ans" =~ ^[Yy]$ ]] || { echo "aborted"; return 1; }
     printf '%s\n' "$matched" | xargs rm -f
     # Trim index entries
@@ -204,7 +220,8 @@ cmd_clear() {
 }
 
 cmd_count() {
-  local n; n=$(($(wc -l < "$LESSONS_INDEX") - 1))
+  # v0.7.5: coerce_int on wc output (Cygwin CR-taint defense).
+  local n; n=$(( $(coerce_int "$(wc -l < "$LESSONS_INDEX")" 0) - 1 ))
   echo "$n"
 }
 
diff --git a/lib/nc-document.sh b/lib/nc-document.sh
index 746aa76..1195527 100755
--- a/lib/nc-document.sh
+++ b/lib/nc-document.sh
@@ -131,7 +131,9 @@ fi
   fi
 
   # ─── Threads inventory ───
-  printf '## Threads (%d matched in %d site(s))\n\n' "${#MATCHES[@]}" "$(printf '%s\n' "${MATCHES[@]}" | awk -F'|' '{print $1}' | sort -u | wc -l | tr -d ' ')"
+  # v0.7.5: tr -cd '0-9' instead of tr -d ' ' — Cygwin wc.exe CR-taint would
+  # otherwise crash `printf '%d'` with "invalid number".
+  printf '## Threads (%d matched in %d site(s))\n\n' "${#MATCHES[@]}" "$(printf '%s\n' "${MATCHES[@]}" | awk -F'|' '{print $1}' | sort -u | wc -l | tr -cd '0-9')"
   printf '| Site | Thread | Process | Direction | Port | Host | Type |\n'
   printf '|---|---|---|---|---|---|---|\n'
   for line in "${MATCHES[@]}"; do
@@ -229,4 +231,4 @@ fi
 } | out_target
 
 [ -n "$OUT" ] && printf 'nc-document: wrote %s (%d matched threads across %d site(s))\n' \
-  "$OUT" "${#MATCHES[@]}" "$(printf '%s\n' "${MATCHES[@]}" | awk -F'|' '{print $1}' | sort -u | wc -l | tr -d ' ')" >&2
+  "$OUT" "${#MATCHES[@]}" "$(printf '%s\n' "${MATCHES[@]}" | awk -F'|' '{print $1}' | sort -u | wc -l | tr -cd '0-9')" >&2
diff --git a/lib/nc-engine.sh b/lib/nc-engine.sh
index 109ba36..e7c44f0 100755
--- a/lib/nc-engine.sh
+++ b/lib/nc-engine.sh
@@ -36,6 +36,17 @@ JOURNAL="$LIB_DIR/journal.sh"
 die() { printf 'nc-engine: %s\n' "$*" >&2; exit 1; }
 warn() { printf 'nc-engine: %s\n' "$*" >&2; }
 
+# v0.7.5: shared CR-safety primitives (coerce_int / strip_cr / read_clean).
+# Source if available; otherwise inline minimal fallbacks so a partial
+# install doesn't break the y/N prompts.
+if [ -r "$LIB_DIR/cygwin-safe.sh" ]; then
+  # shellcheck disable=SC1090,SC1091
+  . "$LIB_DIR/cygwin-safe.sh"
+else
+  coerce_int() { local r="${1:-}" d="${2:-0}" c; c=$(printf '%s' "$r" | tr -cd '0-9'); printf '%s' "${c:-$d}"; }
+  strip_cr() { local v="${1:-}"; printf '%s' "${v//$'\r'/}"; }
+fi
+
 # Source journal so journaled actions can call journal_write
 [ -f "$JOURNAL" ] && . "$JOURNAL" || warn "journal.sh not available — actions will not be reversible"
 
@@ -55,7 +66,10 @@ journal_action() {
   local action="$1" target="$2" detail="${3:-}"
   local sessdir="$LARRY_HOME/journal/${LARRY_SESSION_ID:-engine-$(date +%Y-%m-%d-%H%M%S)-$$}"
   mkdir -p "$sessdir" 2>/dev/null
-  local idx; idx=$(printf '%03d' $(($(find "$sessdir" -name '[0-9]*.engine' 2>/dev/null | wc -l) + 1)))
+  # v0.7.5: coerce_int on wc output — Cygwin wc.exe can suffix the count
+  # with \r on a CRLF terminal which then crashes the surrounding $(( + 1 )).
+  local _cnt; _cnt=$(coerce_int "$(find "$sessdir" -name '[0-9]*.engine' 2>/dev/null | wc -l)" 0)
+  local idx; idx=$(printf '%03d' $((_cnt + 1)))
   local entry="$sessdir/${idx}_${action}_${target//\//_}.engine"
   {
     printf 'action: %s\ntarget: %s\nwhen: %s\nhost: %s\nhciroot: %s\nhcisite: %s\ndetail: %s\n' \
@@ -111,6 +125,8 @@ run_action() {
   if [ "$confirm" != "yes" ]; then
     printf '  proceed? [y/N]: '
     read -r ans </dev/tty 2>/dev/null || ans=""
+    # v0.7.5: strip CR so a Cygwin pty's `Y\r` matches `^[Yy]$`.
+    ans="${ans//$'\r'/}"
     [[ "$ans" =~ ^[Yy]$ ]] || { echo "  DENIED by user"; return 1; }
   fi
 
@@ -139,6 +155,8 @@ cmd_resend() {
   esac
   printf '\nRESEND-%s  thread=%s  file=%s\n  $ %s\n  proceed? [y/N]: ' "${kind^^}" "$thread" "$file" "$cmd"
   read -r ans </dev/tty 2>/dev/null || ans=""
+  # v0.7.5: strip CR so a Cygwin pty's `Y\r` matches `^[Yy]$`.
+  ans="${ans//$'\r'/}"
   [[ "$ans" =~ ^[Yy]$ ]] || { echo "  DENIED"; return 1; }
   journal_action "resend-$kind" "$thread" "file=$file"
   eval "$cmd"
@@ -150,6 +168,8 @@ cmd_route_test() {
   local cmd="$thread route_test $file"
   printf '\nROUTE-TEST  thread=%s  input=%s\n  $ %s\n  proceed? [y/N]: ' "$thread" "$file" "$cmd"
   read -r ans </dev/tty 2>/dev/null || ans=""
+  # v0.7.5: strip CR so a Cygwin pty's `Y\r` matches `^[Yy]$`.
+  ans="${ans//$'\r'/}"
   [[ "$ans" =~ ^[Yy]$ ]] || { echo "  DENIED"; return 1; }
   journal_action "route-test" "$thread" "file=$file"
   eval "$cmd"
@@ -161,6 +181,8 @@ cmd_testxlate() {
   local cmd="testxlate $xlate $xltfile"
   printf '\nTESTXLATE xlate=%s file=%s\n  $ %s\n  proceed? [y/N]: ' "$xlate" "$xltfile" "$cmd"
   read -r ans </dev/tty 2>/dev/null || ans=""
+  # v0.7.5: strip CR so a Cygwin pty's `Y\r` matches `^[Yy]$`.
+  ans="${ans//$'\r'/}"
   [[ "$ans" =~ ^[Yy]$ ]] || { echo "  DENIED"; return 1; }
   journal_action "testxlate" "$xlate" "file=$xltfile"
   eval "$cmd"
@@ -173,6 +195,8 @@ cmd_tpstest() {
   local cmd="tpstest $msgfile $procs"
   printf '\nTPSTEST msgfile=%s procs=%s\n  $ %s\n  proceed? [y/N]: ' "$msgfile" "$procs" "$cmd"
   read -r ans </dev/tty 2>/dev/null || ans=""
+  # v0.7.5: strip CR so a Cygwin pty's `Y\r` matches `^[Yy]$`.
+  ans="${ans//$'\r'/}"
   [[ "$ans" =~ ^[Yy]$ ]] || { echo "  DENIED"; return 1; }
   journal_action "tpstest" "$msgfile" "procs=$procs"
   eval "$cmd"
diff --git a/lib/nc-find.sh b/lib/nc-find.sh
index 55087f5..0add465 100755
--- a/lib/nc-find.sh
+++ b/lib/nc-find.sh
@@ -229,5 +229,7 @@ case "$FORMAT" in
 esac
 
 # Emit count to stderr
-n=$(wc -l < "$RESULTS" | tr -d ' ')
-[ "$FORMAT" = "table" ] && printf '\n%d match(es)\n' "$n" >&2
+# v0.7.5: tr -cd '0-9' instead of tr -d ' ' — Cygwin wc.exe CR-taint defense
+# (printf '%d' "5\r" fails with "invalid number").
+n=$(wc -l < "$RESULTS" | tr -cd '0-9')
+[ "$FORMAT" = "table" ] && printf '\n%d match(es)\n' "${n:-0}" >&2
diff --git a/lib/nc-insert-protocol.sh b/lib/nc-insert-protocol.sh
index 5aa3dfc..4295150 100755
--- a/lib/nc-insert-protocol.sh
+++ b/lib/nc-insert-protocol.sh
@@ -34,6 +34,16 @@ JOURNAL="$LIB_DIR/journal.sh"
 
 die() { printf 'nc-insert-protocol: %s\n' "$*" >&2; exit 1; }
 
+# v0.7.5: shared CR-safety primitives.  awk-emitted line numbers feed
+# `$((end_line - 1))` / `head -n $((start_line - 1))` / `tail -n +$((... + 1))`
+# arithmetic and shell positionals; a CR-tainted awk would crash all three.
+if [ -r "$LIB_DIR/cygwin-safe.sh" ]; then
+  # shellcheck disable=SC1090,SC1091
+  . "$LIB_DIR/cygwin-safe.sh"
+else
+  coerce_int() { local r="${1:-}" d="${2:-0}" c; c=$(printf '%s' "$r" | tr -cd '0-9'); printf '%s' "${c:-$d}"; }
+fi
+
 # Source journal so we can call journal_write directly
 # shellcheck disable=SC1090
 . "$JOURNAL"
@@ -95,6 +105,9 @@ cmd_insert() {
                      }
                    }' "$nc")
       [ -n "$end_line" ] || die "anchor protocol not found: $anchor"
+      # v0.7.5: coerce_int — awk-emitted NR can have a trailing CR on
+      # Cygwin-awk; would crash $((end_line + 1)) arithmetic.
+      end_line=$(coerce_int "$end_line" 0)
       head -n "$end_line" "$nc"  > "$tmp"
       printf '\n' >> "$tmp"
       cat "$block_file" >> "$tmp"
@@ -106,6 +119,8 @@ cmd_insert() {
       local start_line
       start_line=$("$NCP" protocol-line "$nc" "$anchor" 2>/dev/null)
       [ -n "$start_line" ] || die "anchor protocol not found: $anchor"
+      # v0.7.5: coerce_int — protocol-line is awk-based; CR-taint defense.
+      start_line=$(coerce_int "$start_line" 0)
       head -n $((start_line - 1)) "$nc" > "$tmp"
       cat "$block_file" >> "$tmp"
       printf '\n' >> "$tmp"
@@ -194,6 +209,13 @@ cmd_add_route() {
   fi
   [ -n "$dx_end" ] || die "could not locate end of DATAXLATE block in protocol $prot"
 
+  # v0.7.5: coerce_int on every awk-emitted line number before it lands in
+  # arithmetic (head -n / tail -n +N) — Cygwin awk.exe CR-taint defense.
+  start=$(coerce_int "$start" 0)
+  end=$(coerce_int "$end" 0)
+  dx_start=$(coerce_int "$dx_start" 0)
+  dx_end=$(coerce_int "$dx_end" 0)
+
   # Indent the route content to match the DATAXLATE inner indentation (8 spaces typical).
   local indent="        "
   local indented_route; indented_route=$(awk -v IND="$indent" '{print IND $0}' "$route_file")
diff --git a/lib/nc-msgs.sh b/lib/nc-msgs.sh
index e5e0841..5de3d49 100755
--- a/lib/nc-msgs.sh
+++ b/lib/nc-msgs.sh
@@ -37,6 +37,15 @@ NC_SELF="$0"
 LIB_DIR="$(cd "$(dirname "$NC_SELF")" && pwd)"
 HL7F="$LIB_DIR/hl7-field.sh"
 
+# v0.7.5: shared CR-safety primitives (Cygwin/MobaXterm date.exe and wc.exe
+# emit CR-tainted output that crashes the arithmetic in parse_time_ms).
+if [ -r "$LIB_DIR/cygwin-safe.sh" ]; then
+  # shellcheck disable=SC1090,SC1091
+  . "$LIB_DIR/cygwin-safe.sh"
+else
+  coerce_int() { local r="${1:-}" d="${2:-0}" c; c=$(printf '%s' "$r" | tr -cd '0-9'); printf '%s' "${c:-$d}"; }
+fi
+
 die() { printf 'nc-msgs: %s\n' "$*" >&2; exit 1; }
 
 THREAD=""
@@ -107,6 +116,9 @@ locate_smatdb() {
 }
 
 # Parse time expression -> unix ms
+# v0.7.5: every `ts=$(date ... +%s)` capture is routed through coerce_int
+# before it lands in `$((ts * 1000))` — Cygwin date.exe can produce a
+# CR-tainted epoch which would crash with "invalid arithmetic operator".
 parse_time_ms() {
   local expr="$1"
   [ -z "$expr" ] && return 0
@@ -118,13 +130,15 @@ parse_time_ms() {
   # GNU date and BSD date differ. Try GNU first (-d EXPR), fall back to BSD (-jf or -v).
   local ts=""
   if ts=$(date -d "$expr" +%s 2>/dev/null); then
-    printf '%s' "$((ts * 1000))"; return
+    ts=$(coerce_int "$ts" 0); printf '%s' "$((ts * 1000))"; return
   fi
   # BSD date — try `-v` shorthand for relative times
   if echo "$expr" | grep -qE '^[0-9]+ (second|minute|hour|day|week|month|year)s? ago$'; then
     local n unit
     n=$(echo "$expr" | awk '{print $1}')
     unit=$(echo "$expr" | awk '{print $2}' | sed 's/s$//')
+    # n came from awk on a shell-local string — clean it for the arithmetic below.
+    n=$(coerce_int "$n" 0)
     local flag
     case "$unit" in
       second) flag="S" ;;
@@ -135,14 +149,14 @@ parse_time_ms() {
       month)  flag="m" ;;
       year)   flag="y" ;;
     esac
-    ts=$(date -v "-${n}${flag}" +%s 2>/dev/null) && { printf '%s' "$((ts * 1000))"; return; }
+    ts=$(date -v "-${n}${flag}" +%s 2>/dev/null) && { ts=$(coerce_int "$ts" 0); printf '%s' "$((ts * 1000))"; return; }
   fi
   # BSD date with -jf
   if ts=$(date -jf "%Y-%m-%d %H:%M:%S" "$expr" +%s 2>/dev/null); then
-    printf '%s' "$((ts * 1000))"; return
+    ts=$(coerce_int "$ts" 0); printf '%s' "$((ts * 1000))"; return
   fi
   if ts=$(date -jf "%Y-%m-%d" "$expr" +%s 2>/dev/null); then
-    printf '%s' "$((ts * 1000))"; return
+    ts=$(coerce_int "$ts" 0); printf '%s' "$((ts * 1000))"; return
   fi
   die "could not parse time expression: $expr"
 }
@@ -215,7 +229,8 @@ awk -v RS=$'\x1e' -v FS=$'\x1f' -v outdir="$TMP_OUT" '
   }
 ' "$TMP_OUT/raw.bin"
 
-MSG_COUNT=$(ls "$TMP_OUT"/msg_*.bin 2>/dev/null | wc -l | tr -d ' ')
+# v0.7.5: coerce_int on wc output — Cygwin wc.exe CR-taint defense.
+MSG_COUNT=$(coerce_int "$(ls "$TMP_OUT"/msg_*.bin 2>/dev/null | wc -l)" 0)
 KEPT=0
 
 # Parse a single filter expression. Returns path / op / expected via globals.
@@ -432,10 +447,14 @@ case "$FORMAT" in
         typ=$(printf '%s' "$meta" | awk -F'\t' '{print $2}')
         src=$(printf '%s' "$meta" | awk -F'\t' '{print $3}')
         dst=$(printf '%s' "$meta" | awk -F'\t' '{print $4}')
-        if [ "$tm" -gt 100000000000 ] 2>/dev/null; then
-          tm_h=$(date -r $((tm/1000)) 2>/dev/null || date -d "@$((tm/1000))" 2>/dev/null || echo "$tm")
+        # v0.7.5: coerce_int on the time column before any arithmetic / integer
+        # compare.  The meta TSV is written by awk above; on Cygwin a
+        # Windows-native awk could emit CRLF rows and `$1` then carries a CR.
+        tm_i=$(coerce_int "$tm" 0)
+        if [ "$tm_i" -gt 100000000000 ]; then
+          tm_h=$(date -r $((tm_i/1000)) 2>/dev/null || date -d "@$((tm_i/1000))" 2>/dev/null || echo "$tm_i")
         else
-          tm_h="$tm"
+          tm_h="$tm_i"
         fi
         printf '===== msg %d  time=%s  type=%s  src=%s  dst=%s =====\n' "$KEPT" "$tm_h" "$typ" "$src" "$dst"
         case "$FORMAT" in
diff --git a/lib/nc-regression.sh b/lib/nc-regression.sh
index a0d8f00..722761a 100755
--- a/lib/nc-regression.sh
+++ b/lib/nc-regression.sh
@@ -52,6 +52,16 @@ NCI="$LIB_DIR/nc-inbound.sh"
 NCM="$LIB_DIR/nc-msgs.sh"
 HL7DIFF="$LIB_DIR/hl7-diff.sh"
 
+# v0.7.5: shared CR-safety primitives (coerce_int).  The phase loops use
+# `wc -c | tr -d ' '` to count delimiter bytes — Cygwin wc.exe can leak \r
+# which then crashes the `[ "$got" -ge "$COUNT" ]` integer test.
+if [ -r "$LIB_DIR/cygwin-safe.sh" ]; then
+  # shellcheck disable=SC1090,SC1091
+  . "$LIB_DIR/cygwin-safe.sh"
+else
+  coerce_int() { local r="${1:-}" d="${2:-0}" c; c=$(printf '%s' "$r" | tr -cd '0-9'); printf '%s' "${c:-$d}"; }
+fi
+
 die() { printf 'nc-regression: %s\n' "$*" >&2; exit 1; }
 say() { printf 'nc-regression: %s\n' "$*" >&2; }
 
@@ -286,7 +296,8 @@ phase_2() {
         say "  [dry-run] would sample $COUNT msgs from $thread → $input"
       else
         HCISITEDIR="$sitedir" "$NCM" "$thread" --limit "$COUNT" --format raw > "$input" 2>/dev/null
-        local got; got=$(tr -cd $'\x1c' < "$input" | wc -c | tr -d ' ')
+        # v0.7.5: coerce_int on wc output — Cygwin wc.exe can emit \r.
+        local got; got=$(coerce_int "$(tr -cd $'\x1c' < "$input" | wc -c)" 0)
         say "  sampled $thread → $input ($got messages)"
       fi
     fi
@@ -439,7 +450,10 @@ phase_5() {
         "$HL7DIFF" "${diff_args[@]}" --format text "$destfile" "$b_pair" 2>/dev/null || true
       } > "$report"
       echo "| \`$thread\` | \`$destname\` | $count | [report](./$(basename "$report")) |" >> "$diff_index"
-      total_diff=$((total_diff + count))
+      # v0.7.5: coerce_int — defends against (a) Cygwin awk emitting a CR-
+      # tainted count from hl7-diff and (b) the legitimate `?` fallback above
+      # which would otherwise crash `$((total_diff + ?))` arithmetic.
+      total_diff=$((total_diff + $(coerce_int "$count" 0)))
       say "  $thread → $destname: $count diff(s)"
     done < <(find "$a_dir" -maxdepth 1 -type f 2>/dev/null)
   done < "$OUT/inbounds.txt"
diff --git a/lib/nc-smat-diff.sh b/lib/nc-smat-diff.sh
index 30b3abc..e969e36 100755
--- a/lib/nc-smat-diff.sh
+++ b/lib/nc-smat-diff.sh
@@ -28,6 +28,15 @@ NCM="$LIB_DIR/nc-msgs.sh"
 HL7F="$LIB_DIR/hl7-field.sh"
 HL7DIFF="$LIB_DIR/hl7-diff.sh"
 
+# v0.7.5: shared CR-safety primitives — A_COUNT/B_COUNT/DIFFS_TOTAL all feed
+# `%d` printf and arithmetic; Cygwin wc.exe CR-taint would crash them.
+if [ -r "$LIB_DIR/cygwin-safe.sh" ]; then
+  # shellcheck disable=SC1090,SC1091
+  . "$LIB_DIR/cygwin-safe.sh"
+else
+  coerce_int() { local r="${1:-}" d="${2:-0}" c; c=$(printf '%s' "$r" | tr -cd '0-9'); printf '%s' "${c:-$d}"; }
+fi
+
 die() { printf 'nc-smat-diff: %s\n' "$*" >&2; exit 1; }
 
 THREAD=""
@@ -101,8 +110,9 @@ printf 'nc-smat-diff:\n  thread: %s\n  A: %s/%s\n  B: %s/%s\n  limit: %d  ignore
 dump_side "$ENV_A" "$SITE_A" "$OUT/a"
 dump_side "$ENV_B" "$SITE_B" "$OUT/b"
 
-A_COUNT=$(wc -l < "$OUT/a/index.tsv" | tr -d ' ')
-B_COUNT=$(wc -l < "$OUT/b/index.tsv" | tr -d ' ')
+# v0.7.5: coerce_int on wc output — Cygwin wc.exe CR-taint defense.
+A_COUNT=$(coerce_int "$(wc -l < "$OUT/a/index.tsv")" 0)
+B_COUNT=$(coerce_int "$(wc -l < "$OUT/b/index.tsv")" 0)
 printf 'A: %d msgs   B: %d msgs\n\n' "$A_COUNT" "$B_COUNT" >&2
 
 # Pair messages by key
@@ -145,7 +155,9 @@ while IFS= read -r key; do
       "$HL7DIFF" --ignore "$IGNORE" "$a_files" "$b_files" 2>/dev/null
     } > "$report"
     echo "| \`$key\` | $cnt | [report](./diff/$(basename "$report")) |" >> "$SUMMARY"
-    DIFFS_TOTAL=$((DIFFS_TOTAL + ${cnt:-0}))
+    # v0.7.5: coerce_int — defends against both Cygwin awk CR-taint AND the
+    # legitimate `?` fallback that would crash arithmetic.
+    DIFFS_TOTAL=$((DIFFS_TOTAL + $(coerce_int "$cnt" 0)))
   fi
 done < <(printf '%s\n%s\n' "$A_KEYS" "$B_KEYS" | sort -u)
 
diff --git a/lib/nc-table.sh b/lib/nc-table.sh
index ca0b48b..fc7053f 100755
--- a/lib/nc-table.sh
+++ b/lib/nc-table.sh
@@ -123,7 +123,10 @@ modify_via_csv() {
     journal_write "$target" "$new"
   else
     # No journal — direct write with simple backup
-    [ -f "$target" ] && cp -p "$target" "${target}.larry-bak.$(date +%s)"
+    # v0.7.5: strip non-digits from date — Cygwin date.exe could yield
+    # "1779999999\r" which would produce a path with embedded CR.
+    local _ts; _ts=$(date +%s | tr -cd '0-9')
+    [ -f "$target" ] && cp -p "$target" "${target}.larry-bak.${_ts:-0}"
     mv "$new" "$target"
     echo "(no journal available; backup at ${target}.larry-bak.<ts>)"
   fi
diff --git a/lib/oauth.sh b/lib/oauth.sh
index 96ad0eb..8625446 100755
--- a/lib/oauth.sh
+++ b/lib/oauth.sh
@@ -100,6 +100,25 @@ jqf() {
   jq "$@" < "$file" | tr -d '\r'
 }
 
+# v0.7.5: coerce_int / strip_cr / read_clean have moved to lib/cygwin-safe.sh
+# so the entire cloverleaf-larry tool family can share the same CR-defense
+# primitives.  Source it from a sibling lib/ directory; fall back to a local
+# definition if the file is missing (defensive — oauth.sh ships as part of
+# the same MANIFEST so cygwin-safe.sh should always be on disk too).
+_OAUTH_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" 2>/dev/null && pwd)"
+if [ -r "$_OAUTH_DIR/cygwin-safe.sh" ]; then
+  # shellcheck disable=SC1090,SC1091
+  . "$_OAUTH_DIR/cygwin-safe.sh"
+else
+  # Inlined fallback — keep oauth.sh self-contained if a partial install
+  # delivers oauth.sh but not cygwin-safe.sh.
+  coerce_int() {
+    local raw="${1:-}" default="${2:-0}"
+    local cleaned; cleaned=$(printf '%s' "$raw" | tr -cd '0-9')
+    printf '%s' "${cleaned:-$default}"
+  }
+fi
+
 urlenc() {
   # Minimal RFC3986-ish URL encoder for the bits we need (spaces, /, :)
   local s="$1"
@@ -206,7 +225,10 @@ EOF
     exit 1
   fi
 
-  local now; now=$(date +%s)
+  # v0.7.5: coerce_int on date +%s — same Cygwin CR-taint defense applied
+  # to the cmd_ensure operands.  Passing "1779999999\r" to jq's `tonumber`
+  # fails with "tonumber requires string|number, got string ...".
+  local now; now=$(coerce_int "$(date +%s)" 0)
   umask 077
   # Write to a .new sidecar first, validate it parses + has the required keys,
   # then atomically mv into place. If jq fails mid-pipe, $OAUTH_FILE is never
@@ -247,7 +269,8 @@ cmd_refresh() {
     return 1
   fi
 
-  local now; now=$(date +%s)
+  # v0.7.5: coerce_int on date +%s — see cmd_login.
+  local now; now=$(coerce_int "$(date +%s)" 0)
   # Force tight perms on the sidecar at create() time — cmd_refresh historically
   # didn't set umask before the tempfile write, so the .new file inherited the
   # process default (often 0022 → 0644). On Cygwin where chmod-after-the-fact
@@ -307,14 +330,18 @@ cmd_ensure() {
   local fetched_at expires_in
   fetched_at=$(jqf "$OAUTH_FILE" -r '.fetched_at // 0')
   expires_in=$(jqf "$OAUTH_FILE" -r '.expires_in // 3600')
-  # Extra paranoia (v0.6.6): the v0.6.5 /oauth-debug surfaced "syntax error:
-  # invalid arithmetic operator" — diagnosed as CR contamination from CRLF
-  # JSON files (now stripped in jqf). Belt-and-suspenders: coerce via printf
-  # to a pure integer so ANY residual junk (whitespace, NULs, alpha glitches)
-  # falls back to 0 instead of crashing the arithmetic expression.
-  fetched_at=$(printf '%d' "${fetched_at:-0}" 2>/dev/null || echo 0)
-  expires_in=$(printf '%d' "${expires_in:-3600}" 2>/dev/null || echo 3600)
-  local now; now=$(date +%s)
+  # v0.7.5: coerce EVERY operand that will enter an arithmetic / integer-test
+  # context — fetched_at, expires_in, AND now — through coerce_int.  The first
+  # two come from a JSON file (jqf already strips \r but garbage values are
+  # still possible).  The third comes from `date +%s`, which on a Cygwin pty
+  # where Windows-native date.exe shadows Cygwin date can return a CR-tainted
+  # value like "1779999999\r" — that lands one line later in `$((expires_at -
+  # now))` and crashes with "invalid arithmetic operator (error token is "")".
+  # See Deliverables/2026-05-27-cloverleaf-larry-oauth-arithmetic-fix.md for
+  # the full diagnosis from Bryan's v0.7.3 work-box trace.
+  fetched_at=$(coerce_int "$fetched_at" 0)
+  expires_in=$(coerce_int "$expires_in" 3600)
+  local now; now=$(coerce_int "$(date +%s)" 0)
   local expires_at=$((fetched_at + expires_in))
   local left=$((expires_at - now))
   dbg "ensure: fetched_at=$fetched_at expires_in=$expires_in now=$now expires_at=$expires_at left=${left}s"
@@ -350,9 +377,11 @@ cmd_status() {
   fetched_at=$(jqf "$OAUTH_FILE" -r '.fetched_at // 0')
   expires_in=$(jqf "$OAUTH_FILE" -r '.expires_in // 3600')
   scope=$(jqf "$OAUTH_FILE" -r '.scope // "(unknown)"')
-  fetched_at=$(printf '%d' "${fetched_at:-0}" 2>/dev/null || echo 0)
-  expires_in=$(printf '%d' "${expires_in:-3600}" 2>/dev/null || echo 3600)
-  local now; now=$(date +%s)
+  # v0.7.5: same coerce_int discipline as cmd_ensure — see the comment there
+  # for the Cygwin CR-on-date crash diagnosis.
+  fetched_at=$(coerce_int "$fetched_at" 0)
+  expires_in=$(coerce_int "$expires_in" 3600)
+  local now; now=$(coerce_int "$(date +%s)" 0)
   local expires_at=$((fetched_at + expires_in))
   local left=$((expires_at - now))
   printf 'OAuth status:\n'
@@ -423,8 +452,10 @@ cmd_debug() {
   # trailing \r on each line propagates through `jq -r` and crashes downstream
   # bash arithmetic. Show byte counts of CR vs LF so we can spot CRLF taint.
   local cr_count lf_count
-  cr_count=$(tr -dc '\r' < "$OAUTH_FILE" | wc -c | tr -d ' ')
-  lf_count=$(tr -dc '\n' < "$OAUTH_FILE" | wc -c | tr -d ' ')
+  # v0.7.5: coerce_int on wc output — Cygwin wc -c can emit trailing \r on
+  # a CRLF terminal which would tank the `-gt 0` integer test downstream.
+  cr_count=$(coerce_int "$(tr -dc '\r' < "$OAUTH_FILE" | wc -c)" 0)
+  lf_count=$(coerce_int "$(tr -dc '\n' < "$OAUTH_FILE" | wc -c)" 0)
   printf '  line endings:  CR=%s LF=%s' "$cr_count" "$lf_count"
   if [ "$cr_count" -gt 0 ]; then
     printf '  (CRLF detected — v0.6.6 jqf strips these defensively)\n'
@@ -438,10 +469,10 @@ cmd_debug() {
   fetched_at=$(jqf "$OAUTH_FILE" -r '.fetched_at // 0')
   expires_in=$(jqf "$OAUTH_FILE" -r '.expires_in // 3600')
   scope=$(jqf "$OAUTH_FILE" -r '.scope // "(missing)"')
-  # Belt-and-suspenders integer coercion (see cmd_ensure for the why).
-  fetched_at=$(printf '%d' "${fetched_at:-0}" 2>/dev/null || echo 0)
-  expires_in=$(printf '%d' "${expires_in:-3600}" 2>/dev/null || echo 3600)
-  local now; now=$(date +%s)
+  # v0.7.5: coerce_int on all three operands (see cmd_ensure for the why).
+  fetched_at=$(coerce_int "$fetched_at" 0)
+  expires_in=$(coerce_int "$expires_in" 3600)
+  local now; now=$(coerce_int "$(date +%s)" 0)
   local expires_at=$((fetched_at + expires_in))
   local left=$((expires_at - now))
   local refresh_at=$((expires_at - 300))
diff --git a/lib/ssh-helper.sh b/lib/ssh-helper.sh
index a066f91..9260dd0 100755
--- a/lib/ssh-helper.sh
+++ b/lib/ssh-helper.sh
@@ -44,6 +44,17 @@ die()  { printf 'ssh-helper: %s\n' "$*" >&2; exit 1; }
 warn() { printf 'ssh-helper: warn: %s\n' "$*" >&2; }
 ok()   { printf 'ssh-helper: %s\n' "$*"; }
 
+# v0.7.5: shared CR-safety primitives.  pull/push use `wc -c | tr -d ' '` to
+# verify byte counts — Cygwin wc.exe can pass through \r and tank the
+# `[ "$got" != "$local_size" ]` comparison.
+_SSH_LIB_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" 2>/dev/null && pwd)"
+if [ -r "$_SSH_LIB_DIR/cygwin-safe.sh" ]; then
+  # shellcheck disable=SC1090,SC1091
+  . "$_SSH_LIB_DIR/cygwin-safe.sh"
+else
+  coerce_int() { local r="${1:-}" d="${2:-0}" c; c=$(printf '%s' "$r" | tr -cd '0-9'); printf '%s' "${c:-$d}"; }
+fi
+
 ensure_layout() {
   mkdir -p "$LARRY_HOME" "$SSH_CREDS_DIR" "$SSH_SOCKETS_DIR" 2>/dev/null
   chmod 700 "$LARRY_HOME" "$SSH_CREDS_DIR" "$SSH_SOCKETS_DIR" 2>/dev/null || true
@@ -72,7 +83,9 @@ cmd_help() {
 
 cmd_hosts() {
   ensure_layout
-  if [ "$(wc -l < "$SSH_HOSTS_FILE")" -le 1 ]; then
+  # v0.7.5: coerce_int on wc output — Cygwin wc.exe CR-taint would tank
+  # the `-le 1` integer test below.
+  if [ "$(coerce_int "$(wc -l < "$SSH_HOSTS_FILE")" 0)" -le 1 ]; then
     echo "no hosts configured. Add with: ssh-helper.sh add <alias> <user@host[:port]>"
     return 0
   fi
@@ -293,9 +306,10 @@ cmd_pull() {
   mkdir -p "$(dirname "$local_path")" 2>/dev/null
 
   # Get remote file size up-front for a partial-transfer sanity check.
+  # v0.7.5: coerce_int on wc output — strips CR + non-digits at the source.
   local remote_size=""
-  remote_size=$(ssh -S "$_RH_SOCK" -p "$_RH_PORT" -o BatchMode=yes "$_RH_ADDR" \
-    "wc -c < $(printf '%q' "$remote") 2>/dev/null" 2>/dev/null | tr -d ' ')
+  remote_size=$(coerce_int "$(ssh -S "$_RH_SOCK" -p "$_RH_PORT" -o BatchMode=yes "$_RH_ADDR" \
+    "wc -c < $(printf '%q' "$remote") 2>/dev/null" 2>/dev/null)" "")
   if [ -z "$remote_size" ] || ! [[ "$remote_size" =~ ^[0-9]+$ ]]; then
     die "remote file not found or not readable: $remote"
   fi
@@ -308,7 +322,8 @@ cmd_pull() {
         -o "BatchMode=yes" \
         -P "$_RH_PORT" \
         "$_RH_ADDR:$remote" "$local_path" 2>"$scp_err"; then
-    local got; got=$(wc -c < "$local_path" 2>/dev/null | tr -d ' ')
+    # v0.7.5: coerce_int on wc output — Cygwin wc.exe CR-taint defense.
+    local got; got=$(coerce_int "$(wc -c < "$local_path" 2>/dev/null)" 0)
     if [ "$got" != "$remote_size" ]; then
       rm -f "$scp_err"
       die "partial transfer: remote=$remote_size bytes, local=$got bytes ($local_path)"
@@ -334,7 +349,8 @@ cmd_push() {
   [ -f "$local_path" ] || die "local file not found: $local_path"
   _resolve_open_master "$alias"
 
-  local local_size; local_size=$(wc -c < "$local_path" 2>/dev/null | tr -d ' ')
+  # v0.7.5: coerce_int on wc output — Cygwin wc.exe CR-taint defense.
+  local local_size; local_size=$(coerce_int "$(wc -c < "$local_path" 2>/dev/null)" 0)
   local scp_err; scp_err=$(mktemp 2>/dev/null || echo "/tmp/larry-scp.err.$$")
   if scp -q \
         -o "ControlPath=$_RH_SOCK" \
@@ -344,8 +360,9 @@ cmd_push() {
         "$local_path" "$_RH_ADDR:$remote" 2>"$scp_err"; then
     # Validate via remote wc -c.
     local got
-    got=$(ssh -S "$_RH_SOCK" -p "$_RH_PORT" -o BatchMode=yes "$_RH_ADDR" \
-      "wc -c < $(printf '%q' "$remote") 2>/dev/null" 2>/dev/null | tr -d ' ')
+    # v0.7.5: coerce_int on wc output (Cygwin wc.exe CR-taint defense).
+    got=$(coerce_int "$(ssh -S "$_RH_SOCK" -p "$_RH_PORT" -o BatchMode=yes "$_RH_ADDR" \
+      "wc -c < $(printf '%q' "$remote") 2>/dev/null" 2>/dev/null)" 0)
     if [ "$got" != "$local_size" ]; then
       rm -f "$scp_err"
       die "partial transfer: local=$local_size bytes, remote=$got bytes ($alias:$remote)"