fix(rename): second review pass on the package rename

- The post-task reclaim skip recognises the legacy application.* embed name,
  so query embeds queued by the previous release do not pay a full collect.
- The Azure compose file mounts host data on /app/{indexes,inputs,vectors},
  where the process actually reads and writes; it mounted /app/application/...
  before the rename and /app/docsgpt/... after it, and nothing wrote to either.
- The offline image check triggers on docsgpt/requirements*.txt again;
  dependabot's pip entry points at docsgpt/.
- install_hint() and its docstring name docsgpt/requirements-<extra>.txt;
  the test asserts the full path.
- application/vectors/ stays ignored: the compose files still mount it.
- The durability QA script quiets the docsgpt logger tree.
- Upgrade note: the three renamed source-sync entries start their timers
  from the upgrade.

docs/content/upgrading.mdx

@@ -106,7 +106,9 @@ alias, so nothing breaks on upgrade, but update these before the alias goes:
 - Celery task names changed with the package (`docsgpt.api.user.tasks.ingest`
   and so on). A worker on this release also accepts the old names, so tasks
   queued before the upgrade still run, and beat rewrites the periodic
-  schedule in Redis on start-up. Nothing to do.
+  schedule in Redis on start-up. The daily, weekly and monthly source-sync
+  timers restart from the upgrade, so the first sync after it can land later
+  than it would have (a monthly sync by up to a month). Nothing to do.
 - Data directories do not move: the compose files keep your indexes, inputs
   and vectors under `application/` in the checkout, where they already are.