Forgejo repository rename / linked pull request synchronization

Environment for both recordings:
- Real T3 Code development server, each revision in its own isolated worktree.
- Fresh T3 databases with T3CODE_DEV_SEED=0. No production database copied.
- Local Forgejo 12 (container image codeberg.org/forgejo/forgejo:12).
- Real fj 0.7.0 authentication, application token stored with fj auth add-token.
- Synthetic evidence account and repository only.
- Server RPC surface; no browser, device, viewport, or theme applies.
- Videos use identical 1440x900 dark terminal styling and play at 1x speed.
- Videos render timestamped stdout recordings; accompanying .cast files are the original recordings.

Reproduce:
1. Start local Forgejo on port 33029, create a synthetic evidence account and
   application token; save the token beside seed.py as forgejo-token (never upload it).
2. Run seed.py seed before-old. It creates main, feature, one changed file,
   and an OPEN pull request. Authenticate fj to
   http://forgejo.127.0.0.1.nip.io:33029 with the same token, using an isolated
   XDG_DATA_HOME for both server runs.
3. In each revision, install with vp i and run:
   T3CODE_DEV_SEED=0 XDG_DATA_HOME=<isolated-data> vp run dev:server
   Read its serverPort. Issue a session into a private file with:
   node apps/server/src/bin.ts auth session issue --base-dir .t3 --token-only
4. Create an empty local git workspace with origin pointing to
   http://forgejo.127.0.0.1.nip.io:33029/evidence/before-old.git.
5. Run node driver.mjs before http://127.0.0.1:<serverPort> <workspace> <session-file>.
   The driver uses real T3 HTTP/RPC calls to create a project/thread and an
   agent-sourced PR link, waits for its initial OPEN snapshot, renames the
   repository, closes the PR, and observes the unchanged link for 80 seconds.
   It does not invoke a test runner or stub any server/provider implementation.
6. Stop the base server. Run seed.py reset to restore the same repository and
   reopen the same PR. Start the head server against its own database, create a
   second workspace with the same origin, and run the identical driver as after.
7. render-recording.py session.cast Before|After <commit> renders each stdout
   recording to an MP4. The .cast timing is preserved at 1x speed.

Observed:
Base 871b00907d0bcf2705224de6c6e90de925c7cbb9: stale OPEN snapshot; automatic
sync fails with HTTP 301. Head fe167c169599b89de948ffbe1ea59943a9a1199c:
automatic sync follows the 301 to a 200 response and stores CLOSED while retaining
the original link key and URL.

AI-assisted; verified with the tests and tools listed above.