chore(graphify): add graph artifacts

[hishamkaram]

Summary

• Add graphify graph artifacts for this repo.
• Add codebase-memory ignore coverage for graphify-out/.
• Ignore graphify local cost, cache, and hook-state files.

Verification

• Ran graphify update . before committing.
• Verified graphify-out/cache/, graphify-out/cost.json, graphify-out/.rebuild.lock, and graphify-out/.pending_changes are ignored while graphify-out/graph.json remains trackable.
• Ran branch guard for chore/graphify-artifacts before push.