Fix three pre-publish issues found in readiness audit

- create_task.py list-tasks: crash on null credentials.provider
  (`creds.get("provider", {})` returns None when key exists but is null;
  switch to `(creds.get("provider") or {})`)

- sitecustomize.py: write hook_status.json after each module, not only
  when both have loaded; S3-only users (B2 module never imported) now
  get a status file from verify instead of "No status file found"

- README: add filesystem find + sqlite3 DB query to the emergency
  recovery section so users can locate their clone path when middlewared
  is down and midclt is unavailable

patch/sitecustomize.py

@@ -219,8 +219,6 @@ def _record_status(fullname: str, ok: bool, detail: str = "") -> None:
     if fullname in _hook_status:
         return  # idempotent: first call wins
     _hook_status[fullname] = {"ok": ok, "detail": detail}
-    if len(_hook_status) < len(_Finder._targets):
-        return  # wait for all patches; _Finder._targets is the canonical count
 
     payload = {
         "patched_at": time.strftime("%Y-%m-%dT%H:%M:%SZ", time.gmtime()),