Add a vision-model screenshot judge to the QA tooling

`tools/screen_designs.py judge` sends each capture together with its concept
mockup to a vision model and asks whether the capture realises the same screen and
layout intent. This covers what pixel/perceptual metrics cannot judge.

- Prompt explicitly ignores art style, fidelity, fonts, and placeholder text, since
  the references are stylised mockups.
- Verdicts are classed match / review (mismatch below --fail-confidence, default
  0.6) / diff (confident mismatch, exits non-zero) / unknown; --json, --only,
  --dry-run, --model supported.
- Reads the repo .env for OPENROUTER_API_KEY without overriding real env vars.
- Default judge model google/gemini-2.5-flash-lite; openai/gpt-4o-mini verified too.

Tests/docs
- 7 new offline tests in tools/test_screen_designs.py (request payload embeds both
  images, JSON/fenced/parts/non-JSON parsing, threshold classification, .env
  loading); 30 Python tests pass.
- Live run: 3 captures match, 3 review, 0 confident diffs.
- README, TODO section moved to DONE, MEMORY. Version 0.2.15.

MEMORY.md

@@ -21,8 +21,8 @@ Session memory for durable decisions, state, and gotchas. Keep concise, remove o
   Windowed control smoke: `godot --path . --script res://src/test/smoke_focus_radial.gd` → exit 0.
 - `main` is in sync with origin. **v0.2.2** tags the session-shell + world-follow-up commit;
   CI builds the portable binaries, NSIS installer, and AppImage on the tag push.
-- Next work: the two remaining TODO sections — the vision-model screenshot judge
-  (`tools/screen_designs.py`, OpenRouter key in `.env`) and editor tooling (GUT / `.tres` venues).
+- Next work: only the optional editor-tooling section remains (GUT plugin, `.tres` venues);
+  everything else in `TODO.md` is complete.
 - Do not re-open `override_access`. Do not bind wand to `W`. Do not remove the radio easter egg.
 
 ## Current State
@@ -95,6 +95,14 @@ Session memory for durable decisions, state, and gotchas. Keep concise, remove o
   `_begin_incident()` now starts one per focused NPC (`has_open_incident()` guard), verbs call
   `_ensure_incident()`, and `ShiftCoordinator._finish_shift()` closes leftovers as `unresolved`
   before building the review.
+- **Vision judge (2026-10-31):** `python3 tools/screen_designs.py judge` sends the capture plus
+  its concept mockup to a vision model (`DEFAULT_JUDGE_MODEL = google/gemini-2.5-flash-lite`,
+  override with `--model`; `openai/gpt-4o-mini` also works). Reads the repo `.env` via
+  `_load_env_file()` (never overrides real env). Verdicts are classed `match` / `review`
+  (mismatch below `--fail-confidence`, default 0.6) / `diff` (confident mismatch → exit 1) /
+  `unknown`. `--dry-run`, `--json`, `--only` supported. The prompt explicitly ignores art style,
+  because the references are stylised mockups; the live run gave 3 match, 3 review, 0 diff.
+  Python tests: `cd tools && python3 -m unittest test_asset_pipeline test_screen_designs`.
 - **String formatting safety (2026-10-31):** `Strings.placeholder_count()` counts `%` specs
   (ignoring `%%`), `fmt()` warns and returns the template when the arg count does not match
   (instead of raising an engine error), and `validate()` lints the table for trailing `%`,