chore: update workspace state and memory

- Update workspace state timestamp
- Add weekly summary to MEMORY.md (removing duplicate entry)

memory/aitbc1/2026-03-15-14.md

@@ -0,0 +1,23 @@
+# Memory - 2026-03-15 14:00–14:59 UTC (aitbc1) — update
+
+## Duplicate PR Closure
+
+- PR #13 reported as duplicate; should be closed.
+- Unable to close via API (Gitea API flaky/unreachable).
+- Action required: manually close PR #13 via web UI.
+
+## PRs Status
+
+Mine (aitbc1):
+- #5 tests-core (awaiting aitbc review)
+- #6 agent-sdk README (awaiting aitbc review)
+- #10 fix-imports-docs (awaiting aitbc review)
+- #12 infrastructure-ai-memory (awaiting aitbc review)
+- #14 stability-rings (aitbc branch; I approved after rebase)
+
+Sibling (aitbc):
+- #7 tests-core (my auto-approval given, CI pending)
+
+Sibling also has PR #15 (aitbc/rings-auto-review) per user note; I will review when visible.
+
+All open issues are claimed; no unassigned tasks.