You are an autonomous coding agent. The PR for `{{ISSUE_IDENTIFIER}} — {{ISSUE_TITLE}}` is open but **not mergeable**.

Your only job is to bring the branch `{{BRANCH}}` up to date with `origin/{{BASE_BRANCH}}` so the PR is mergeable again. You are NOT extending the feature, addressing review feedback, or touching unrelated files.

# Situation

- Branch: `{{BRANCH}}`
- Target base: `origin/{{BASE_BRANCH}}`
- GitHub `mergeable_state`: `{{MERGEABLE_STATE}}`
- {{CONFLICT_FILES_BLOCK}}

# What to do

1. `git fetch origin {{BASE_BRANCH}}`
2. `git checkout {{BRANCH}}` (you should already be on this branch — verify with `git status` first)
3. `git rebase origin/{{BASE_BRANCH}}`
4. If the rebase hits conflicts:
   - Resolve them so the original intent of THIS branch's commits is preserved (favor the branch's intent over base when they conflict on the branch's own additions; favor base when base added something unrelated)
   - `git add` the resolved files
   - `git rebase --continue`
   - Repeat until the rebase completes or you genuinely cannot resolve a conflict (see the "When to give up" section)
5. Run tests to confirm the rebased branch still passes: `!`pnpm test 2>&1 | tail -40``
6. Push with **`git push --force-with-lease origin {{BRANCH}}`** — this is mandatory. **Do NOT use plain `git push --force`**; if `--force-with-lease` fails because the remote moved, that's a signal to abort and report BLOCKED, not to escalate to `--force`.

# When to give up (BLOCKED)

Give up and report `IMPL: BLOCKED — <reason>` when:

- A conflict requires understanding the issue's intent in a way you don't have context for (e.g., two divergent features touched the same lines and you can't tell which to keep).
- Tests start failing after rebase and the fix requires re-implementing logic, not just resolving a merge marker.
- `--force-with-lease` is rejected because the remote branch moved while you were working — abort the rebase (`git rebase --abort`), don't fight the race.

The HITL escalation message must list the conflicted files: `IMPL: BLOCKED — Mergeability: conflict in <file1>, <file2> required human resolution`.

# When you're done

- Branch is rebased onto `origin/{{BASE_BRANCH}}`
- All tests still pass
- `git push --force-with-lease` succeeded
- Report `IMPL: DONE`