An upstream merge that conflicts starts one converge run for the crew #4236

A conflicting upstream head now starts one converge run for the crew, once per head. The new tests, bun x tsc --noEmit and the converge and following tests pass. I ran test/autonomy*, test/crew* and test/brief* once, and 312 passed and 2 failed. I saw only one of the failure names: "a young lock that blocks checkout is recovered by a fresh clone" in the "run the last forge left running" suite. That is a git-lock recovery test in code I didn't touch. I didn't rerun it or check it against main, so I can't say whether it fails there too, or what the second failure was. I did not run the full suite.

What changed

• One run per head: when a check reads "conflict", src/actions/upstream_follow.ts (convergeConflict) opens one issue titled Upstream: conflict at <tip7>. It names the upstream URL, the head and the conflicting files. It picks a builder and queues one converge run with the summary upstream moved: <files>.
• Repeat checks: a second check of the same head finds that issue, open or closed, and starts nothing. A new head gets a new issue and run.
• Autonomy off: the conflict is only noted on the follow row (error = "conflict"). No issue and no run. Autonomy is read fresh from the repository, not from the object the check was handed.
• Brief: src/crew/brief.ts gains an upstream form. It names the upstream URL, fetches the staged refs/upstream-follow/<branch>, requires a real merge (no rebase, squash or cherry-pick) and quotes file names as outside text. src/crew/runner.ts selects it for issues titled Upstream: … and strips the new upstream moved: prefix to get the file list.
• Landing (also in this change): src/crew/autonomy.ts lands a pull that carries upstream's commits as a merge rather than a squash, so the next check doesn't count them again. This comes from #3722; I included it because a squashed resolution would defeat the point.
• Tests: in test/upstream_follow.test.ts, one conflicting head gives exactly one converge run and one issue, even after repeated checks, and the brief names the URL, ref and files. With autonomy off there is no run and no issue.

Left out

• #3722's wider layer (the followWords autonomy status line, the pages, the API, and the clean-merge pull's changes).
• A builder-less repository gets the issue but no run.
• The tests count run rows rather than stubbing the runner; queueAgentRun only queues a run, so no runner executes.

Try it: bun test test/upstream_follow.test.ts.

Closes #3979

A conflicting upstream head now starts one converge run for the crew, once per head. The new tests, bun x tsc --noEmit and the converge and following tests pass. I ran test/autonomy*, test/crew* and test/brief* once, and 312 passed and 2 failed. I saw only one of the failure names: "a young lock that blocks checkout is recovered by a fresh clone" in the "run the last forge left running" suite. That is a git-lock recovery test in code I didn't touch. I didn't rerun it or check it against main, so I can't say whether it fails there too, or what the second failure was. I did not run the full suite.

What changed

• One run per head: when a check reads "conflict", src/actions/upstream_follow.ts (convergeConflict) opens one issue titled Upstream: conflict at <tip7>. It names the upstream URL, the head and the conflicting files. It picks a builder and queues one converge run with the summary upstream moved: <files>.
• Repeat checks: a second check of the same head finds that issue, open or closed, and starts nothing. A new head gets a new issue and run.
• Autonomy off: the conflict is only noted on the follow row (error = "conflict"). No issue and no run. Autonomy is read fresh from the repository, not from the object the check was handed.
• Brief: src/crew/brief.ts gains an upstream form. It names the upstream URL, fetches the staged refs/upstream-follow/<branch>, requires a real merge (no rebase, squash or cherry-pick) and quotes file names as outside text. src/crew/runner.ts selects it for issues titled Upstream: … and strips the new upstream moved: prefix to get the file list.
• Landing (also in this change): src/crew/autonomy.ts lands a pull that carries upstream's commits as a merge rather than a squash, so the next check doesn't count them again. This comes from #3722; I included it because a squashed resolution would defeat the point.
• Tests: in test/upstream_follow.test.ts, one conflicting head gives exactly one converge run and one issue, even after repeated checks, and the brief names the URL, ref and files. With autonomy off there is no run and no issue.

Left out

• #3722's wider layer (the followWords autonomy status line, the pages, the API, and the clean-merge pull's changes).
• A builder-less repository gets the issue but no run.
• The tests count run rows rather than stubbing the runner; queueAgentRun only queues a run, so no runner executes.

Try it: bun test test/upstream_follow.test.ts.

This change adds the two missing tests and moves the logic they cover into functions the tests call. It also answers the main-failure question and decides to keep the landing change. bun x tsc --noEmit and test/upstream_follow.test.ts plus test/following.test.ts pass (55 tests). I did not re-run the autonomy/crew/brief group, which previously showed 2 failures.

What changed

• Landing strategy: the merge-or-squash choice is now landingStrategy(app, repo, pull, baseOid) in src/crew/autonomy.ts, and landGated calls it. A new test in test/upstream_follow.test.ts checks a real proposal pull, whose head is the staged upstream tip, and an ordinary pull on the same repository. The upstream pull lands as a merge, and the ordinary one squashes. I made the function always return "squash" and the test failed, so it does catch that.
• Runner brief choice: the runner's two inline pieces are now conflictFilesOf(summary) and convergeFollowing(app, repo, issue, user) in src/crew/runner.ts, and work calls them. The new test covers four things:

- An issue titled Upstream: … gets the upstream brief (URL, branch and staged ref). - An ordinary issue gets none. - The upstream moved: prefix is stripped from the run summary. - parent moved: and main moved: are still stripped.

• Failures on main: the one failure I saw by name, "a young lock that blocks checkout is recovered by a fresh clone" in test/crew-interrupted.test.ts, fails the same way on a clean checkout of origin/main, so it is not from this change. I never identified the second failure from the earlier run, so I can't say whether it also fails on main.
• Landing change kept, not split out: without the merge strategy a squashed upstream resolution would defeat the follow, since the next check would count upstream's commits again. It now has a test that fails without it.

I merged main into the branch, resolved both conflicts, and pushed. The type check is clean, and the upstream-follow and autonomy tests pass (52 in total). I did not run the full bun test here, because it ran past the shell timeout. The forge's check will run it on this push.

• src/actions/upstream_follow.ts: I kept the imports from both sides. This branch needs runGit, mergeBase, openIssue and the converge-run helpers. main added putFollow, upstreamUrl, isSafeRef, canAdmin and migrateUrl for the admin follow settings.
• src/crew/autonomy.ts: I kept this branch's landingStrategy(...) call and dropped main's one-line isUpstreamPull(...) check. landingStrategy covers the same case, since upstream pulls still land as a merge and others as a squash. isUpstreamPull is still exported from src/core/upstream_follow.ts, but nothing in src/ calls it any more.
• test/upstream_follow.test.ts: The merge left getRepoById imported twice, so I removed one import.

A conflicting upstream head now starts one converge run for the crew, with one issue per head. With autonomy off, it stays at the note on the follow row. This push addresses juniper's review. The type check is clean and the upstream-follow and autonomy tests pass (52). I haven't run the full bun test here, so the forge's check on this push is the first full run.

• landGated doc: landingStrategy now sits above the "Land one gated step…" comment, so landGated has its doc back (src/crew/autonomy.ts).
• isUpstreamPull: I deleted it from src/core/upstream_follow.ts. Nothing in src/ or test/ used it, and landingStrategy makes the same merge-versus-squash choice.
• README: the conflict bullet in the repository-following section now says that a conflicting head opens one issue and queues one converge run, and that with autonomy off the row's note is all there is.

I did not change the title-prefix keying ("Upstream: ") for the brief and the dedupe, since you marked it non-blocking. Any writer can open an issue with that title, so it could get the upstream brief or suppress a head. Keying on the run or the follow row would be sturdier and is worth a follow-up.