Fix five quality findings; expand recovery and restore documentation

patch_ui.py:
- Write Angular bundle atomically via tmp + os.replace, matching the pattern
  already used by _record_status. Prevents a corrupt bundle if the write is
  interrupted mid-boot.

sitecustomize.py:
- Tighten _record_status count barrier comment to name _Finder._targets as
  the canonical count, making the coupling visible to future editors.

uninstall.sh:
- Verify middlewared restarted cleanly after uninstall, with journalctl
  guidance on failure — matching recover.sh's existing pattern.

apply.sh:
- Change second line of site-packages error block from WARNING: prefix
  (misleading for an instructional message) to a plain Run: hint.

create_task.py:
- Guard __doc__ against None in epilog extraction so -OO does not crash.

README.md:
- Split Emergency recovery into three named subsections: middlewared won't
  start, web UI is blank or broken (corrupt bundle recovery), and backend
  verify shows FAIL. Each gives direct commands and escalation steps.
- Add Restoring from a TrueCloud Backup section: finding the restic binary,
  gathering credentials, provider-specific env var setup for B2 and S3,
  listing and restoring snapshots, and operational notes on restore hygiene.
- Clarify that hook_status.json is written once both target modules have
  loaded (not necessarily at the instant middlewared starts).

patch/sitecustomize.py

@@ -189,7 +189,7 @@ def _record_status(fullname: str, ok: bool, detail: str = "") -> None:
         return  # idempotent: first call wins
     _hook_status[fullname] = {"ok": ok, "detail": detail}
     if len(_hook_status) < len(_Finder._targets):
-        return  # wait until all patches have reported before writing
+        return  # wait for all patches; _Finder._targets is the canonical count
 
     payload = {
         "patched_at": time.strftime("%Y-%m-%dT%H:%M:%SZ", time.gmtime()),