#1794 PR-2 — Deferred worktree advisory delivery

Why this PR exists

PR-1 (#1797) fixed the literal-named-directory bug from #1794 by switching worktree-lifecycle-logger to outputSilentSuccess() on command-type WorktreeCreate. That fix was correct — CC does not consume additionalContext on WorktreeCreate — but it had a side effect: the monorepo sparsePaths nudge was silenced. It now only reaches ctx.log() (dev-facing), not the model.

Mechanism

Two-step bridge across the event boundary:

1. writeWorktreeAdvisory(advisory, name, projectDir) — called from the WorktreeCreate hook when monorepo + no sparsePaths. Writes .claude/state/worktree-advisory-<slug>.md.
2. prompt/worktree-advisory-consumer — UserPromptSubmit hook reads all .claude/state/worktree-advisory-*.md on the next prompt, concatenates, deletes the files, injects via outputPromptContext() (allow-listed for UserPromptSubmit).

Properties

• One-shot. Files are deleted after read, so advisories never repeat.
• Best-effort. I/O errors do not throw — fall back to ctx.log() as in PR-1.
• Concurrency-safe. Two worktree creates in flight write to different files (slug-keyed); consumer reads in sorted order.
• Side-effect-free read. Consumer returns silent success when nothing pending (cheap: one readdirSync per prompt).

Tests

• worktree-advisory.test.ts — 22 tests for writeWorktreeAdvisory + consumeWorktreeAdvisories + slugify (file system round-trip via mkdtempSync)
• worktree-advisory-consumer.test.ts — 8 tests for the hook (silent paths, single + multi advisory, project_dir fallback, no leak on non-advisory files, defensive on null input)
• Total: 30 tests, all passing

Hook count

Total hooks: 195 → 196 (one new prompt/ hook).

This page exists to satisfy the M119 playground gate.

Closes #1794 follow-up (PR-2). Refs #1797 (PR-1).