fix(agent): only attach PR URLs from gh pr create

[adboio]

Summary

• Gate PR-URL attachment on the originating bash command containing gh pr create, eliminating false positives from gh pr view, gh search prs, gh pr list, etc.
• Extract the detection logic into a shared pr-url-detector helper, replacing two byte-identical implementations in the desktop service and the cloud agent-server.
• Thread the bash command through _meta.claudeCode.bashCommand in the SDK→ACP converter so consumers don't have to correlate tool_call → tool_call_update.

Why

Today any GitHub PR URL printed by a bash tool gets latched onto TaskRun.output.pr_url. That fires downstream Slack notifications and PR-status UI off URLs the agent merely referenced (e.g. when looking up a historical PR). A real instance of this misfire produced four "Pull request opened" Slack messages from a single gh pr view call.

The most robust signal that a URL is a PR the agent just created is: the command was gh pr create. git push only ever prints pull/new/<branch>, which doesn't match the URL regex; gh pr edit/merge/view/list/search operate on existing PRs.

Test plan

• `pnpm --filter @posthog/agent test` — 13 new helper tests + 4 new agent-server regression cases pass (317 / 317)
• `pnpm --filter code test` — desktop suite green (982 / 982)
• `pnpm --filter @posthog/agent typecheck` and `pnpm --filter code typecheck` clean
• `pnpm lint` clean
• Manual end-to-end smoke: with `pnpm dev`, ask the agent to look up an existing PR via `gh pr view ` and confirm `pr_url` is not attached and no Slack notification fires; then ask it to create a PR via `gh pr create` and confirm the existing flow still works.

Generated-By: PostHog Code
Task-Id: 302a50dd-3e6e-4f4c-abbf-4ca0e0f9250d

[greptile-apps]

Prompt To Fix All With AI

Fix the following 1 code review issue. Work through them one at a time, proposing concise fixes.

---

### Issue 1 of 1
packages/agent/src/pr-url-detector.test.ts:7-137
**Prefer parameterised tests**

All 13 test cases follow the exact same shape — vary `toolName`, `bashCommand`, `toolResponse`/`content`, and expect a URL or `null`. Per the project's simplicity rules, this should be a single `it.each()` table rather than 13 separate `it()` blocks.

```typescript
it.each([
  ["gh pr create (string response)", "Bash", 'gh pr create --title "x"', `${PR_URL}\n`, undefined, PR_URL],
  ["gh pr create (object stdout)",   "Bash", "gh pr create --fill",      { stdout: `${PR_URL}\n` }, undefined, PR_URL],
  ["gh pr view ignored",             "Bash", `gh pr view ${PR_URL}`,      { stdout: PR_URL },        undefined, null],
  // … remaining rows
])(
  "%s",
  (_desc, toolName, bashCommand, toolResponse, content, expected) => {
    expect(extractCreatedPrUrl({ toolName, bashCommand, toolResponse, content }))
      .toBe(expected);
  },
);
```

This also makes it trivial to add new cases without boilerplate.

_{Reviews (1): Last reviewed commit: "fix(agent): only attach PR URLs from gh ..." | Re-trigger Greptile}

[joshsny]

thank youuuu

[adboio]

will merge after a bit more testing 🫡

[adboio]

• fix(agent): only attach PR URLs from gh pr create #1964 👈 (View in Graphite)
• main

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[adboio]

Merge activity

• May 5, 8:52 PM UTC: @adboio merged this pull request with Graphite.