docs(arch): realism leads the quality list; performance moves to the end

Owner decision: prioritise realism, keep the performance target but put it last.

- Quality goals reordered (01 + combined architecture.md): 1 visual realism,
  2 geographic fidelity, 3 walkability/usability, 4 reproducibility/portability,
  5 provenance, 6 performance efficiency.
- Quality requirements (10 + combined) reordered to match, with two new realism
  requirements (façade reads like the photographs; placement within ~1 m) and the
  quality scenarios renumbered so QS-1 is the reference comparison and QS-9 the
  frame rate.
- Both documents carry the same guard so the order cannot become an excuse:
  performance is a floor, not a preference - 60 FPS at 1440p without frame
  generation must be met at every release; if realism cannot fit, the realism scope
  is cut deliberately and recorded, never the frame rate. Walkability outranks
  realism in one direction: a block you fall through is not a demo.
- Solution strategy and 'quality achievement' now lead with realism and describe
  performance as a budget rather than a driver.
- Docs/release-checks.md: the performance check is the last check, with that reason
  stated; ROADMAP gains a 'Quality priority' section; AGENTS.md gains the tie-break
  rule beside the existing scope-cutting rule.

Docs/Architecture/04_solution_strategy.md

@@ -30,7 +30,8 @@ All modelling and geographic processing live outside the game project in `Art/`,
 
 ## Quality achievement
 
-- **Performance**: dynamic-only lighting (no build step, no static shadow maps), world-space-noise materials (cheap procedural variation), minimal overdraw (simple street-level geometry).
+- **Realism first**: reference photography and measured data drive every façade decision; renders are compared against the photographs with `Tools/visual_loop.py`, and a façade is built from the shared 4.96 m module kit so the street wall reads consistently. Materials are authored in Unreal with world-aligned generated textures, and lighting is fixed daytime so a shot is comparable between runs.
+- **Performance as a budget, not a driver**: dynamic-only lighting (no build step, no static shadow maps), world-space-noise materials (cheap procedural variation), minimal overdraw for street-level geometry, and a 60 FPS at 1440p floor that every release must meet. It closes the quality list because it constrains how much realism fits, not what the block should look like.
 
 - **Walkability**: complex-as-simple collision on terrain (C++ helper forces the flag on the asset), block-all collision on every site mesh, swept transect QA verifies zero raycast holes.