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

Owner decision: prioritise realism, keep the performance target but put it last.
Re-applied on a branch after the first attempt landed directly on main (reverted
there; see b8209ce).

- Quality goals (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 realism
  requirements added (a façade reads like the photographs; placement within ~1 m)
  and the scenarios renumbered so QS-1 is the reference comparison, QS-9 the frame
  rate.
- Guard on both documents 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, cut the realism scope deliberately and
  record it, never the frame rate. Walkability outranks realism in one direction: a
  block you fall through is not a demo.
- Solution strategy and 'quality achievement' lead with realism and describe
  performance as a budget, not a driver.
- Docs/release-checks.md: the performance check is the last section and the per-
  version check list now opens with realism and closes with performance.
- ROADMAP gains a 'Quality priority' section; AGENTS.md gains the tie-break rule
  beside the existing scope-cutting rule.

MEMORY.md

@@ -420,3 +420,19 @@ Scope: facts and traps that cost time to establish. Planned work lives in [TODO.
 - Owner reviewed the four demo captures locally and approved the set. Signoff recorded in `Docs/reviews/0.1.4-review.md` (7/7 items) and in the per-shot `Approved` column of `Screenshots/README.md`.
 - The three geometry items that `0.1.4` did not finish — retail neighbours from their own references, hero fluting/motto band, blockout cleaning — move to a new **`0.1.5` Façade finishing** patch rather than growing this one, plus a much-needed **1440p performance re-measure** (625 kit actors have never been measured; `0.1.0` measured 414 fps).
 - Decision recorded because it sets a precedent: finish and sign off a version when its _stated_ scope is done, and carry leftover scope into the next patch — do not let a patch accumulate unmeasured geometry.
+
+## 2026-11-09 — quality priority flipped: realism first, performance last
+
+- Owner decision: realism leads; performance closes the quality list. Applied in
+  `Docs/Architecture/01_introduction_and_goals.md`, `10_quality_requirements.md`,
+  `04_solution_strategy.md`, the combined `architecture.md`, `Docs/release-checks.md`
+  (performance section now last, with the reason), `ROADMAP.md` (a "Quality priority"
+  section) and `AGENTS.md` (the tie-break rule next to the scope-cutting rule).
+- Ordering used: 1 visual realism, 2 geographic fidelity, 3 walkability/usability,
+  4 build reproducibility/portability, 5 provenance, 6 performance.
+- **Both revisions carry the same guard so the order cannot be used as an excuse:**
+  performance is a *floor*, not a preference — 60 FPS at 1440p without frame
+  generation must be met at every release, and if realism cannot fit, the realism
+  scope is cut deliberately and recorded in `CHANGELOG.md`, never the frame rate.
+  Walkability outranks realism in one direction: a block the player falls through is
+  not a demo.