[knight22-21]

Summary

• add a debounced background project watcher while an indexed DevAgent session is active
• synchronize changed, created, and deleted source files through CodePrism's incremental updater
• ignore generated and dependency directories
• add deterministic watcher tests

Validation

• pytest -q tests/test_codeprism_watcher.py tests/test_security_gate.py tests/test_phase8.py tests/test_phase15.py tests/test_phase36.py
• ruff check devagent/codeprism/watcher.py devagent/codeprism/client.py devagent/agent/flows.py tests/test_codeprism_watcher.py
• python -m compileall -q devagent
• git diff --check

The watcher is debounced and performs incremental updates; it does not run a full index for every edit.