fix: scope project skills by tenant

doc/llm/log/20260818_00.md

@@ -0,0 +1,9 @@
+# issue-42 tenant skills
+
+- AMCS2 MCP calls were attempted but cancelled by the environment, so this local fallback log captures the required thought summary.
+- Model selection: Tuesday Claude primary was unavailable because its OAuth access token expired; Codex gpt-5.5 was used as the final fallback.
+- `tea issue 42` crashed before returning issue data, and Gitea DNS was unavailable, so the fix was inferred from the issue branch name and tenant-skill code paths.
+- Implemented tenant enforcement for project skill links in `internal/store/skills.go`: add, remove, and list now require the project and skill to belong to the active tenant when a tenant context is present.
+- Added focused tests for the tenant predicate helper in `internal/store/skills_test.go`.
+- Verification: `go test ./internal/store -v`, `go test ./internal/tools -v`, and `go test ./internal/store ./internal/tools` passed.
+- Full `go test ./...` was attempted but failed on existing environment constraints: missing `ui/dist` embedded assets and sandbox-blocked `httptest` listener sockets.