Add "Worker Bee" agent for autonomous CI-driven PR iteration

[fbmcipher]

Please see discussion #4047 for more details.

• Introduces "Worker Bee", a general coding agent for Copilot that autonomously manages the full lifecycle of code changes – branching, committing, opening draft PRs, and iterating on CI failures until all checks pass.
• This replaces the unsteered Copilot coding agent
• Solves the core problem: Copilot's default agent doesn't check CI status and hallucinates about test results. PP uses GitHub MCP server tools to poll workflow runs, retrieve logs, and fix failures in a loop.
• Agent persona ("confident, reliable, diligent engineer") is intentionally chosen to activate internal model vectors that reduce reward-hacking under pressure.
• Handles edge cases: respects explicit requests for failing regression tests (verifying only the intended test fails), can invoke
  /puppeteer-update-snapshots for intentional UI changes, and escalates to the user when uncertain.
• Safety cap of 5 CI fix-push cycles before stopping and escalating.
• Tested on two prior issues (Test: Caret moves to incorrect thought from note #3973, Add failing test: gestures broken after dragging duplicate thought to Home #4045) where the default agent failed
• WB produced correct results on both (see discussion thread for detailed results)

[fbmcipher]

@raineorshine Agent renamed and ready to merge!

Re: the failing TDD tests. I noticed these new actions and wanted to discuss them with you yesterday at our AI session, but we ran out of time. I think let's hold off on a full discussion about these until the time feels right – but just wanted to flag that the tests seem a little flaky here?

I'm not 100% on what they're supposed to do, but I can see that they detect changed files. The TDD workflows fail because they detect changes to all these files, which I haven't changed in this PR:

package.json
packages/webview/package.json
src/actions/__tests__/swapParent.ts
src/actions/formatSelection.ts
src/actions/moveThought.ts
src/colors.config.ts
src/commands/newUncle.ts
src/commands/note.ts
src/commands/undo.ts
src/components/ColorPicker.tsx
src/components/Note.tsx
src/components/VirtualThought.tsx
src/e2e/puppeteer/__tests__/color.ts
src/selectors/getSortedRank.ts
src/util/compareThought.ts
src/util/noteValue.ts
yarn.lock

=== Unit test files ===
src/actions/__tests__/swapParent.ts

=== Puppeteer test files ===
src/e2e/puppeteer/__tests__/color.ts

=== iOS test files ===


=== Non-test application files ===
src/actions/formatSelection.ts
src/actions/moveThought.ts
src/colors.config.ts
src/commands/newUncle.ts
src/commands/note.ts
src/commands/undo.ts
src/components/ColorPicker.tsx
src/components/Note.tsx
src/components/VirtualThought.tsx
src/selectors/getSortedRank.ts
src/util/compareThought.ts
src/util/noteValue.ts

My fbmcipher:persistent-pusher branches off of an earlier commit in main, so maybe it's picking up the changes made in main since then, too.

[raineorshine]

Thank you and sorry for the inconvenience! I'm still working out some issues with the TDD workflow. See my Discord message in the dev channel for full details.