docs(core): record unlimited stock recycling as an intentional rules decision

Resolves the Draw-1 recycle question from the June 500-game audit:
unlimited recycling with upstream score penalties is deliberate,
matching mainstream digital solitaire rather than strict 3-pass
tournament rules. The difficulty seed catalog and the winnable-deal
solver are verified under this rule, so a hard pass limit must not be
introduced casually.

- ARCHITECTURE.md: new 'Rules decisions' note in the solitaire_core
  section
- GameState::draw() doc comment points at the decision record
- New lock-in test draw_one_recycling_is_unlimited_by_design asserts
  10+ recycles are never rejected

Closes #117

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

CHANGELOG.md

@@ -8,6 +8,12 @@ project follows [Semantic Versioning](https://semver.org/).
 
 ### Added
 
+- **Rules decision record: unlimited stock recycling.** Documented in
+  `ARCHITECTURE.md` that unlimited recycling with score penalties (matching
+  mainstream digital solitaire) is intentional, and locked it in with a core
+  test — the difficulty seed catalog and winnable-deal solver are verified
+  under this rule. Resolves the last open finding from the June 500-game
+  audit (issue #117).
 - **Analytics validation runbook.** Documented native Matomo live validation,
   expected event payloads, and the current web/WASM analytics split.
 - **Android smoke-test runbook.** Updated the Android doc with the current