Architect run: thirdshift finds and implements a Strong deepening opportunity unattended

CONTEXT.md

@@ -90,7 +90,7 @@ A **Run** asked to end with its pull request merged rather than left for review,
 _Avoid_: auto-merge (GitHub's own feature, which thirdshift does not use)
 
 **Run notification**:
-A message thirdshift sends when a **Run** or a **Spec run** ends, whatever its outcome (ready, merged, failed or interrupted), to the address given with the email flag or the default in the **User config**. A Run or Spec run sends one only when asked to, by the flag or by the User config; a Spec run's notification lists each **Ticket**'s outcome, and a Ticket's **Run** never sends one of its own. Failing to send one never changes the outcome.
+A message thirdshift sends when a **Run**, a **Spec run** or an **Architect run** ends, whatever its outcome (ready, merged, failed or interrupted; for an Architect run that dispatched nothing, plan published, idea filed, idea already filed or review failed), to the address given with the email flag or the default in the **User config**. Each sends one only when asked to, by the flag or by the User config; a Spec run's notification lists each **Ticket**'s outcome, and a Ticket's **Run** never sends one of its own. An Architect run's notification tells how its **Architecture review** ended, naming the plan or idea issue, and how the Spec run or Run it dispatched ended, which sends none of its own. Failing to send one never changes the outcome.
 _Avoid_: completion email, alert
 
 **User config**:

prompts/README.md

@@ -22,6 +22,7 @@ claude -p --permission-mode auto --plugin-dir <plugin dir> --output-format strea
 | Continuation, with no pull request | Starts the implement session when the Run is a Continuation of an Issue branch that has no pull request. | [continuation.md](continuation.md) |
 | Continuation, with an open pull request | Starts the implement session when the Run is a Continuation of an Issue branch whose pull request is open. | [continuation-pr.md](continuation-pr.md) |
 | Spec review | In a Spec run, starts the Spec review once every Ticket has landed on the Spec branch, before the Spec PR, a draft until then, is marked ready. | [spec-review.md](spec-review.md) |
+| Architecture review | Starts the Architecture review, the session an Architect run opens with, in a worktree at the head of the Base branch. The line naming the focus is left out when the command gives none. | [architecture-review.md](architecture-review.md) |
 | Conflict Repair | Starts a Repair session when merging the Base branch into the Issue branch leaves conflicts. | [conflict-repair.md](conflict-repair.md) |
 | Conflict Repair, on Foreign commits | In a Merge run, starts a Repair session when merging Foreign commits from the Issue branch on origin into the local one leaves conflicts. | [foreign-conflict-repair.md](foreign-conflict-repair.md) |
 | Review Repair | In a Merge run, starts a Repair session once Foreign commits are merged into the Issue branch, to review them from the head the Run last knew as its own before they can be merged. | [review-repair.md](review-repair.md) |

prompts/architecture-review.md

@@ -0,0 +1,28 @@
+<!-- Generated by src/prompts_page.rs from the prompts in src/prompt.rs and their titles and when sentences in src/prompts_page.rs; don't edit. Regenerate with UPDATE_PROMPTS=1 cargo test prompts_page -->
+
+# Architecture review
+
+Starts the Architecture review, the session an Architect run opens with, in a worktree at the head of the Base branch. The line naming the focus is left out when the command gives none.
+
+```
+/thirdshift:improve-codebase-architecture
+
+This is an Architecture review of the base branch <base>: this worktree is checked out at its head on origin, on no branch.
+
+Focus the review on: <focus>
+
+Find the deepening opportunities with /thirdshift:improve-codebase-architecture, using /thirdshift:codebase-design for the vocabulary. Skip any that an open issue already covers, and take the top recommendation.
+
+If it is Strong, settle its design yourself and publish it as the plan with /thirdshift:to-spec and /thirdshift:to-tickets: a Spec with Tickets, or a single Ticket when one session is enough. Label the plan's top issue, the Spec or the single Ticket, `needs-triage`, not `ready-for-agent`: thirdshift marks it ready once you are done.
+
+If it is not Strong, file it as one issue labelled `needs-triage`, unless an open issue already covers it.
+
+Do not commit or push anything. You may edit files here to check an idea: the worktree is thrown away when you finish. A change the plan needs to CONTEXT.md or an ADR is a Ticket's work, not yours.
+
+End your final message with one of these lines, as its last line, with the issue's full URL and nothing else on the line:
+Architecture review plan: <URL of the Spec or the single Ticket you published>
+Architecture review idea: <URL of the issue you filed>
+Architecture review already filed: <URL of the open issue that already covers it>
+
+You run headless: nobody is watching, and ending your turn ends the session. Run tests and other long commands in the foreground, raising the Bash timeout if needed. If a command is moved to the background, wait for that task by its own task id or output file, never by process names or patterns (`pgrep`, `ps | grep`, and the like): other sessions on this machine run the same commands. Never end your turn while a background task you depend on is still running: ending the turn kills it.
+```