feat: v0.10.0 quieter Matrix, worktrees, usage pace, repo diffs, copy reply, turn timer, compact

- Matrix "needs you": ignore Claude's idle reminder (no red, no post); post
  only when no tab is in view, after 60 s, once per session per 10 min, and
  say what is asked. Closes #50
- devdesk new NAME PROJECT --worktree: own checkout on devdesk/NAME,
  cleaned up on end when clean/merged. Closes #44
- Usage meters: reset time, pace warning; Matrix ping past 90% when away.
  Closes #45
- Repo panel lists changed files; click opens the diff. Closes #46
- Copy Claude's last reply (--last-reply). Closes #47
- Turn timer in chip, title and cards. Closes #48
- Compact button at 80% context when idle. Closes #49

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WHRLCCdXYm41Qx5kNhehaP

libexec/devdesk-statusline

@@ -43,6 +43,17 @@ if [[ $session =~ ^[A-Za-z0-9][A-Za-z0-9_-]{0,63}$ ]]; then
     fi
 fi
 
+# Plan usage past DEVDESK_USAGE_WARN: ping Matrix if you're away (devdesk#45).
+# The marker holds the window already warned about, so this stays one read.
+if [[ $session != "" ]] && read -r pct resets < <(jq -rM '.rate_limits.five_hour
+        | select(.used_percentage != null and .resets_at != null)
+        | "\(.used_percentage | floor) \(.resets_at)"' <<<"$input" 2>/dev/null) &&
+    [ "$pct" -ge "${DEVDESK_USAGE_WARN:-90}" ] &&
+    [ "$(cat "${DEVDESK_STATE_DIR:-/var/lib/devdesk}/usage-warned" 2>/dev/null)" != "$resets" ]; then
+    setsid -f "${DEVDESK_LIBEXEC:-/usr/lib/devdesk}/devdesk-notify-matrix" --usage "$pct" "$resets" \
+        </dev/null >/dev/null 2>&1 || true
+fi
+
 # Footer line: session · model · context % and tokens · plan use. ANSI colour numbers, not
 # RGB, so the browser's dark or light palette applies (devdesk#31). Claude sends
 # rate_limits only to Pro/Max subscribers; there .cost is an API-price estimate,