session-end: passing test edits are recorded as failed outcomes

[LeonEvo1103]

Summary

hooks/session-end.js records ordinary test-code additions such as assert.equal(...) as a failed evolution outcome, even when the assertion is valid and the tests pass.

Verified on main at 3048fb73910a0a8944f74fb2e70abd5752a60b2f.

Reproduction

1. Create a temporary Git repository with a committed test file.

2. Add this line to the tracked file without committing it:

   assert.equal(1 + 1, 2);

3. Run hooks/session-end.js with COPILOT_WORKSPACE_DIR pointing to the temporary repository and MEMORY_GRAPH_PATH pointing to a temporary JSONL file.

4. Inspect the emitted message and memory entry.

Actual result

Signals: [test_failure]

{
  "signals": ["test_failure"],
  "outcome": {
    "status": "failed",
    "score": 0.3
  }
}

Expected result

Adding test syntax must not be treated as evidence that the session failed. Without explicit test execution evidence, the hook should record a neutral/unknown result or avoid inferring failure.

Cause

• hooks/_signals.js:58-64 treats assert. and expect( as test_failure keywords.
• The code-line filter at hooks/_signals.js:69-102 does not recognize Git diff lines prefixed with +, so added test code reaches keyword matching.
• hooks/session-end.js:335-342 maps any test_failure signal directly to failed / 0.3.

Impact

Common Node/Jest test additions systematically pollute evolution memory with false failed outcomes.