fix: v0.9.1 robustness cleanups

- run_resume falls back to a new conversation only when the transcript file
  is gone; other failures end at the menu with the recorded id intact.
- The SessionStart hook resolves the session name under the registry lock;
  rename holds it across tmux rename-session and the registry move
  (dd_registry_locked, nestable).
- dd_load_env parses KEY=value like systemd instead of sourcing the files.
- devdesk-deploy: DPkg::Lock::Timeout, explicit FAILED lines on stdout and in
  the log; the hook answers synchronously and CI checks the HTTP status.
  logrotate for the deploy log.
- postinst drops duplicate terminal-features entries; hooks sweep stale
  temp files.

Closes #12

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

libexec/devdesk-inbox.sh

@@ -50,8 +50,7 @@ cmd_answer() {
 dd_transcript() {
     local id
     id=$(dd_registry_get "$1" claude_session_id)
-    [[ $id =~ ^[0-9a-f-]{36}$ ]] || return 1
-    compgen -G "${CLAUDE_CONFIG_DIR:-$HOME/.claude}/projects/*/$id.jsonl" | head -n1
+    dd_convo_file "$id"
 }
 
 # --peek SESSION: what the session is doing and the last exchange, from the end