agent: lumotia-rebrand — final residuals (HANDOVER + arch-map readme + ui-kit React fn)

Phase 15.1 final-grep residuals:
- HANDOVER.md "Rebrand note" + Phase 10b row updated to reflect that
  the cascade completed 2026/05/13 (15 phases, both repos, QC-gated).
- HANDOVER.md two surviving sed artefacts: "Lumotia -> Lumotia" line
  restored to "Magnotia -> Lumotia" historical context;
  MAGNOTIA_LLM_TEST_MODEL test gate -> LUMOTIA_LLM_TEST_MODEL.
- src/design-system/ui_kits/index.html: MagnotiaApp React function ->
  LumotiaApp (sed boundary missed the no-separator boundary).
- docs/architecture-map/README.md: MAGNOTIA_LLM_TEST_MODEL doc note.

Preserved (audit trail):
- docs/handovers/ — historical handover docs.
- docs/superpowers/plans/2026-05-12-engine-slop-residuals.md and
  -area-a-storage-errors-survey.md — describe the slop-pass work
  using the names current at the time.
- build/index.html, package-lock.json — regenerate on next build/install.

cargo test --workspace: 339 pass / 0 fail. npm run check: 0 errors.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docs/architecture-map/README.md

@@ -117,7 +117,7 @@ Open items surfaced by the slice maps. Each slice's README has its own debt sect
 - **No prompt versioning.** No `PROMPT_VERSION` constant. Cached cleanup output will silently drift across prompt revisions.
 - **Trivial-true GPU cross-check (commit `052265b`).** `gpu_offloaded` derived from `use_gpu && gpu_layers >= n_layer` is provably true today because `gpu_layers = u32::MAX` whenever `use_gpu` is set. Real residency observability needs llama.cpp log parsing.
 - **MAX_CONTEXT_TOKENS is a process-wide cap of 8192** regardless of model tier. The 27B tier has a much larger native context that is never advertised.
-- **`MAGNOTIA_LLM_TEST_MODEL` env-var gate** is the only thing keeping the LLM smoke tests honest. Worth documenting in a contributor note.
+- **`LUMOTIA_LLM_TEST_MODEL` env-var gate** is the only thing keeping the LLM smoke tests honest. Worth documenting in a contributor note.
 - **British English regex misses `-ing` forms** of `-ize` verbs (e.g. `organizing` slips through unconverted).
 - **Multi-token phrase repetition not detected** by the anti-hallucination filter. Five repetitions of `"thank you"` does not trigger.