Require TODO updates for every task

TODO.md

@@ -4,6 +4,7 @@
 - This file is both backlog and handover log.
 - Future plans written in this file should be written in Korean by default.
 - When a meaningful coding/documentation task is completed, the workflow should aim to finish with a push to the git remote when the remote is available.
+- Every task handled in this repository should add or update a corresponding work note in `TODO.md` before the task is considered complete.
 - Every meaningful change should record:
   - what changed
   - why it changed
@@ -266,6 +267,16 @@
   - backend debug broadcasts
 
 ## Recent Change Log
+- Date: `2026-03-24`
+- What changed:
+  - Added an operating rule that every completed task in this repository should also be reflected in `TODO.md`.
+- Why it changed:
+  - The repository workflow was tightened so the handover file stays current after every task instead of only after larger batches of work.
+- How it was verified:
+  - `git diff -- TODO.md`
+- What is still risky or incomplete:
+  - This rule still depends on disciplined execution in each turn, so future work should keep verifying that `TODO.md` is updated before commit/push.
+
 - Date: `2026-03-24`
 - What changed:
   - Added a frontend-only `Video / Image` media-type toggle to Zone A.