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/patch_ui.py

@@ -109,11 +109,17 @@ def main():
 
     patched, count = FIND.subn(REPLACE, content)
 
+    tmp = path + ".tmp"
     try:
-        with open(path, "w", encoding="utf-8") as fh:
+        with open(tmp, "w", encoding="utf-8") as fh:
             fh.write(patched)
+        os.replace(tmp, path)
     except OSError as exc:
         print(f"[truecloud-patch] ERROR: Could not write {path}: {exc}")
+        try:
+            os.unlink(tmp)
+        except OSError:
+            pass
         return
 
     print(f"[truecloud-patch] UI bundle patched ({count} replacement(s)): {path}")