ci: add release concurrency guards + document release gotchas

Concurrency: add a per-ref concurrency group (cancel-in-progress: false — a publish must never be cancelled mid-flight) to the four v*-tag publishers that lacked one (release-pythinker-cli, linux-installer, windows-installer, homebrew-tap), so the whole v* pipeline is consistently guarded against overlapping same-tag runs. scoop-bucket, docker, and promote-release already had it. Resolves the concurrency nit deferred from #46.

Docs: add a 'Release pipeline gotchas' section to AGENTS.md capturing the traps hit while shipping 0.28.0 — GitHub tag filters are glob (not regex/extglob, so ( ) are literal and v+([0-9])... matches nothing), a pushed tag runs the workflow at the tagged commit (re-tag onto the fixed commit), and main's required_conversation_resolution makes all-green checks insufficient to merge when a review thread is unresolved.

[skip changelog] — CI/docs hardening, no user-facing product change.

Author: elkaix

.github/workflows/homebrew-tap.yml

@@ -11,6 +11,9 @@ on:
         required: true
         type: string
 
+concurrency:
+  group: homebrew-tap-${{ github.ref }}
+  cancel-in-progress: false
 
 env:
   FORCE_JAVASCRIPT_ACTIONS_TO_NODE24: "true"

.github/workflows/linux-installer.yml

@@ -12,6 +12,9 @@ on:
         required: true
         type: string
 
+concurrency:
+  group: linux-installer-${{ github.ref }}
+  cancel-in-progress: false
 
 env:
   FORCE_JAVASCRIPT_ACTIONS_TO_NODE24: "true"

.github/workflows/release-pythinker-cli.yml

@@ -5,6 +5,10 @@ on:
     tags:
       - "v[0-9]+.[0-9]+.[0-9]+"
 
+concurrency:
+  group: release-pythinker-cli-${{ github.ref }}
+  cancel-in-progress: false
+
 permissions:
   contents: write
 

.github/workflows/windows-installer.yml

@@ -12,6 +12,9 @@ on:
         required: true
         type: string
 
+concurrency:
+  group: windows-installer-${{ github.ref }}
+  cancel-in-progress: false
 
 env:
   FORCE_JAVASCRIPT_ACTIONS_TO_NODE24: "true"

AGENTS.md

@@ -422,3 +422,26 @@ user or release workflow explicitly asks for that package.
    resolvable by the install scripts and the in-app updater. If a builder is
    re-run after promotion it flips the Release back to prerelease; recover by
    running `promote-release.yml` via `workflow_dispatch` for that tag.
+
+### Release pipeline gotchas
+
+Hard-won traps — re-check these before and during a release:
+
+- **Tag triggers use GitHub's glob filter, which is NOT regex or ksh extglob.** Every `v*`-triggered
+  workflow (`release-pythinker-cli`, `promote-release`, `linux-installer`, `windows-installer`,
+  `homebrew-tap`, `scoop-bucket`, `docker`) must filter on `"v[0-9]+.[0-9]+.[0-9]+"`. In a GitHub tag
+  filter `(` and `)` are literal characters, so an extglob-style pattern such as
+  `"v+([0-9]).+([0-9]).+([0-9])"` matches no real tag and silently fires **nothing** — the release looks
+  like it "did nothing" with no error anywhere. Do not "modernize" these patterns into extglob/regex.
+- **A pushed tag runs the workflow definition that exists AT the tagged commit.** If you fix a release
+  workflow or its trigger, re-create the tag on the post-fix commit — re-pushing a tag that still points
+  at the pre-fix commit just re-runs the broken definition. Use an annotated tag
+  (`git tag -a vX.Y.Z -m ...`). Pre-flight before re-tagging: confirm nothing shipped yet
+  (`gh release view vX.Y.Z` is "not found" and `https://pypi.org/pypi/pythinker-code/X.Y.Z/json` is 404),
+  then delete the old tag locally and on origin and re-push.
+- **`main` requires conversation resolution, so all-green checks are not sufficient to merge.** If
+  `gh pr view <n> --json mergeStateStatus` shows `BLOCKED` while every required check is `SUCCESS`, look
+  for an unresolved review thread — CodeRabbit can open one even when its commit status reads "Review
+  skipped". Inspect via the `reviewThreads` GraphQL field, verify the finding, reply in-thread, then
+  `resolveReviewThread`. `main` is also squash-only (linear history, `enforce_admins` on), so merge with
+  `gh pr merge --squash`.