Make the vision judge discover cost-effective OpenRouter models

Add openrouter_judge.py to rank live image+JSON models by advertised price,
with ordered fallbacks, auth-error handling and auto selection. Wire both judges
to --model auto, record the model used, and add fake-catalogue/mocked-call
tests. Re-run the judges with the valid key: 13/13 screen designs match, 0 diff;
the Forward+ A/B report records the selected model and ~$0.006 spend. Headless
231/231, Python 94/94.

docs/architecture.md

@@ -37,7 +37,7 @@ This document follows the structure of the arc42 architecture documentation temp
 - **MINOR** — new venues, NPC archetypes, systems, or features that are backward compatible.
 - **PATCH** — bug fixes and small polish that do not change behavior.
 
-The single source of truth for the version is `config/version` in `project.godot` (currently `0.7.1`). Each release is tagged in git as `v<version>` (e.g. `v0.6.0`). The `0.x` series is pre-1.0, so MINOR bumps may introduce breaking changes while the prototype is still stabilizing. `tools/build_releases.sh` and `tools/publish_release.sh` read the version from `project.godot`, so bumping it there is the only required step before a release. The full bump checklist lives in [`RELEASING.md`](RELEASING.md).
+The single source of truth for the version is `config/version` in `project.godot` (currently `0.7.2`). Each release is tagged in git as `v<version>` (e.g. `v0.6.0`). The `0.x` series is pre-1.0, so MINOR bumps may introduce breaking changes while the prototype is still stabilizing. `tools/build_releases.sh` and `tools/publish_release.sh` read the version from `project.godot`, so bumping it there is the only required step before a release. The full bump checklist lives in [`RELEASING.md`](RELEASING.md).
 
 ## 3. Context and Scope