docs: clean up root markdown files and synchronize with v4.4.0 standards

- Relocate legacy implementation_plan.md to docs/contracts/nats-backplane/implementation_plan.md
- Synchronize root documentation (README, README.ko, BOOTSTRAP, BOOTSTRAP.ko, AGENTS, MESSAGING, IMPROVEMENTS) to latest v4.4.0 standards
- Consolidate IMPROVEMENTS.md to single source of truth (5 open / 31 completed tasks 1:1 matching section headers)
- Archive unanimous PASS review reports from Claude, Grok, Codex, and OpenCode along with Plan Rev.2

.agents/reports/reviewer-creator-grok-01/report-30122522.md

@@ -0,0 +1,35 @@
+# Root markdown cleanup review (uncommitted tree on `07cae71`)
+
+- **Reviewer**: `reviewer-creator-grok-01`
+- **Job**: `30122522`
+- **HEAD**: `07cae71` (working tree)
+- **Diff**: `AGENTS.md`, `BOOTSTRAP.md` / `.ko.md`, `IMPROVEMENTS.md`, `MESSAGING.md`, `README.md` / `.ko.md`, `implementation_plan.md` → `docs/contracts/nats-backplane/implementation_plan.md`
+- **Checks**: `git diff --check` clean. Root `*.md`: `AGENTS.md`, `BOOTSTRAP.md`, `BOOTSTRAP.ko.md`, `IMPROVEMENTS.md`, `MESSAGING.md`, `README.md`, `README.ko.md`, `VERSIONS.md`.
+
+Documentation only. No production tests required. Tree re-read independently (same diff as job `01859590`; residuals below still present).
+
+---
+
+## What holds
+
+The NATS backplane plan is off the workspace root and lives next to Issue #5 contracts. The new file records the move date and uses working relative links to `nats-docker/NATS_REPORT.md` and `PRIVATE_SERVER.md`.
+
+`BOOTSTRAP.md` / `.ko.md` list `lib_py/{agents,delegation,loop}` and call `scripts/*.py` shims. `README.md` / `.ko.md` do the same in the skills list and directory tree. `MESSAGING.md` stamps v4.4.0, names `lib_py.delegation` as the body, notes CAS/`dispatch_token`, and marks HMAC as implemented. `AGENTS.md` O-3 still delegates via `run_loop.sh` and names the Python loop runtime.
+
+`IMPROVEMENTS.md` is one ledger: **5 open** (A-2, B-16, B-17, B-18, O-5) and **31 completed**. Header IDs match completed `###` headings. Merge-duplicate B-14/B-15/B-16 blocks are gone. O-2 (P0-2) is still in §5. B-13 notes freeze removal in v4.4.0.
+
+---
+
+## Residuals (non-blocking)
+
+1. **README architecture narrative was not updated.** Skills list and tree mention `lib_py.loop`; Layer A is still “lib.sh + status/resume/stop/create” and Layer B does not mention the CAS engine (`README.md:62-63`, same in `README.ko.md:44-45`).
+2. **Inbound link not updated with the move.** `nats-docker/PRIVATE_SERVER.md:5` still points `implementation_plan.md` at `lac/curriculum/How_To_Use_GENAI/implementation_plan.md`. After this relocate it should be `../docs/contracts/nats-backplane/implementation_plan.md`. `IMPROVEMENTS.md` still names `NATS_REPORT.md` without a path; the file is `nats-docker/NATS_REPORT.md`.
+3. **Stale line number.** B-16 still says `mqtt_common.py:258`; `client_id` is built at `lib_py/delegation/mqtt_common.py:276`.
+4. **BOOTSTRAP parent line** still calls `skills/` “a collection of shell scripts” while listing `lib_py/` under it.
+5. **`AGENTS.md` / `README.md` have no trailing newline.** Pre-existing. `git diff --check` is clean.
+
+No `[ESCALATE: PLANNER]`.
+
+---
+
+[VERDICT: PASS]