# #1794 — WorktreeCreate command-type returns wrong envelope

## Symptom

A literal directory named `{"continue":true,"suppressOutput":true}/` appears in the project root after CC fires a `WorktreeCreate` hook. The chdir call ENAMETOOLONGs or silently mkdirs a stringified-JSON path.

## Root cause

`src/hooks/src/worktree/worktree-lifecycle-logger.ts:115` returned `outputPromptContext(advisory)`, which stamps `hookEventName: 'UserPromptSubmit'` on a `WorktreeCreate` response. CC's `WorktreeCreate` consumer does not read `additionalContext`; it falls back to using the stringified shallow envelope as a chdir target.

## Defense in depth (5 layers)

1. Call site: command-type returns `outputSilentSuccess()`. HTTP branch unchanged.
2. Existing tests updated: `worktree-hook-loading.test.ts` asserts the new silent shape.
3. Dispatcher guard: `src/hooks/bin/output-guard.mjs` + wiring in `run-hook.mjs:509` strips `hookEventName` / `additionalContext` from events that don't consume them. Symmetric to the input-side `isValidPath()` (#1250).
4. Roundtrip test: `lifecycle-output-protocol.test.ts` fires synthetic input at each lifecycle hook and asserts no wrong-event envelope.
5. Opt-out: `ORCHESTKIT_DISABLE_OUTPUT_GUARD=1` for emergency revert without rolling the package.

## Verified

    RUN  v4.1.3 /Users/yonatangross/coding/yonatangross/orchestkit/src/hooks

     Test Files  2 passed (2)
          Tests  26 passed | 1 skipped (27)

Closes #1794.