[draft] feat: add session user review notes

[benvinegar]

Summary

• Adds session-persistent human-authored inline review notes in the diff stream.
• Exposes notes to agents through hunk session note list/get/rm and hunk session review --include-notes.
• Uses GitHub-style inline note location labels like src/core/types.ts R142 / L88.
• Adds controller, projection, and Tuistory PTY coverage for note creation and readback.

Verification

• bun run typecheck
• bun test
• Targeted Tuistory/manual tmux verification for inline note draft/save and session note readback.

This PR description was generated by Pi using GPT-5 (2026-05-10)