* fix: improve openclaw test coverage
* test(openclaw): export stripMemoryTags/extractRecallQuery and add hook integration tests
- Extract stripMemoryTags and extractRecallQuery as exported pure functions
from index.ts so hooks share one implementation and tests cover the real code
- Update before_agent_start to call extractRecallQuery; update agent_end to
call stripMemoryTags instead of duplicating the regex inline
- Rewrite index.test.ts to import the real functions (no more local duplicate)
and add 11 tests for extractRecallQuery covering all envelope-stripping cases
- Add tests/hooks.integration.test.ts: loads the plugin via mock MoltbotPluginAPI
in HTTP mode, spies on client.recall/retain, and exercises all hook behaviours:
excluded providers, short messages, memory injection format, tag stripping,
transcript formatting, array content blocks, metadata, document_id derivation