fix(wizard): make architecture advisor introspection authoritative

[nmorgowicz]

Summary

• Make the Spawn Wizard Quant Advisor consume authoritative GGUF-introspected architecture metadata and reject stale async responses when the selected model changes.
• Remove the obsolete buildHeuristicArch compatibility path and add resolved/degraded/out-of-order browser contract coverage.
• Document the introspection/degraded behavior, archive the completed implementation plan, consolidate exploratory branding assets, and add the Sixcat evaluation integration parking-lot draft.

Test plan

• npm run validate-js
• npm run lint
• cargo fmt -- --check
• cargo test — 1500 passed, 14 ignored
• cargo clippy -- -D warnings
• cargo build --release
• Focused Quant Advisor Playwright regression
• node tests/ui/capture/index.mjs --scenario spawn-wizard
• Canonical Playwright suite — 322 passed, 5 skipped
• git diff --check

The canonical suite still reports the existing capture-manifest diagnostic (strict wizard capture manifest has registered, intentional outputs) while exiting successfully.

Commit override

BEGIN_COMMIT_OVERRIDE
docs(brand): consolidate exploratory concept assets
docs(plans): add Sixcat draft and update architecture cleanup
refactor(wizard): remove stale architecture heuristic
fix(wizard): isolate advisor metadata by model
docs(wizard): archive introspection cleanup plan
docs(wizard): explain introspected quant advisor metadata
END_COMMIT_OVERRIDE