Extract registry pipeline into registry.py with .template.yaml manifest
(per-file SHA256 hashes) for three-way check/update. New workflow MCP tool
with 4 actions (search, install, check, update). CLI commands: gcontext
update and gcontext search. Hide .template.yaml from list_dir/grep/walk.
Re-register module commands on update. Build script for registry.json.
113 tests (24 new in test_workflow_tool.py).
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
