feat: v0.9.0 conversation search, plan usage meters, quiet phone at the desk

- devdesk attach --search (grep + jq over ~/.claude/projects, six files at
  a time) and --resume-convo NAME ID [fork]; devdesk-claude-run passes
  --fork-session once. Search dialog with Resume / Fork / Open.
- statusLine snapshots rate_limits and pr; footer/menu meters with a 90 %
  warning; PR chip on session rows.
- CLAUDE_CLIENT_PRESENCE_FILE per tmux session id; --presence on|off with a
  self-expiring marker; the page heartbeats it while visible.

Closes #24
Closes #25
Closes #26

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

libexec/devdesk-statusline

@@ -1,7 +1,7 @@
 #!/bin/bash
 # Claude Code statusLine command (wired in via claude-settings.json). Claude pipes
 # its status JSON in on every update; we keep a snapshot per DevDesk session for
-# the web UI's Claude Context panel and print a one-line status for Claude's footer.
+# the web UI (context, plan usage, PR) and print a one-line status for Claude's footer.
 # Runs often while Claude streams, so it stays cheap and never fails loudly.
 
 input=$(cat)
@@ -29,7 +29,12 @@ if [[ $session =~ ^[A-Za-z0-9][A-Za-z0-9_-]{0,63}$ ]]; then
                              + (.cache_read_input_tokens // 0)) else null end),
             cost_usd: .cost.total_cost_usd,
             lines_added: .cost.total_lines_added,
-            lines_removed: .cost.total_lines_removed
+            lines_removed: .cost.total_lines_removed,
+            # devdesk#25: plan usage (account-wide) and the pull request of the branch
+            rate_limits: (.rate_limits // null | if . then {
+                five_hour: (.five_hour | if . then {pct: .used_percentage, resets_at} else null end),
+                seven_day: (.seven_day | if . then {pct: .used_percentage, resets_at} else null end)} else null end),
+            pr: (.pr // null | if . then {number, url, review_state, kind} else null end)
         }' <<<"$input" >"$tmp" 2>/dev/null; then
             mv -f "$tmp" "$dir/$session.json"
         else