fix: resolve CI failures on main — lint, hooks validator, and test alignment

- Fix MD012 trailing blank lines in commands/projects.md and commands/promote.md
- Fix MD050 strong-style in continuous-learning-v2 (escape __tests__ as inline code)
- Extract doc-file-warning hook to standalone script to fix hooks validator regex parsing
- Update session-end test to match #317 behavior (always update summary content)
- Allow shell script hooks in integration test format validation

All 992 tests passing.

commands/projects.md

@@ -37,4 +37,3 @@ python3 ~/.claude/skills/continuous-learning-v2/scripts/instinct-cli.py projects
    - Observation event count
    - Last seen timestamp
 3. Also display global instinct totals
-

commands/promote.md

@@ -39,4 +39,3 @@ python3 ~/.claude/skills/continuous-learning-v2/scripts/instinct-cli.py promote
    - Appear in at least 2 projects
    - Meet confidence threshold
 4. Write promoted instincts to `~/.claude/homunculus/instincts/personal/` with `scope: global`
-