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>

ARCHITECTURE.md

@@ -109,6 +109,18 @@ Owns:
 - Achievement unlock condition evaluation
 - Seeded RNG for reproducible deals
 
+**Rules decisions:**
+- **Stock recycling is unlimited in every draw mode — by design.** Extra
+  passes through the stock are discouraged via the upstream score penalty
+  (applied by the `card_game`/`klondike` session), never blocked with a
+  `MoveError`. This matches mainstream digital solitaire (unlimited redeals
+  in Draw-1) rather than strict tournament rules (3-pass cap). It is load-
+  bearing: the difficulty seed catalog and the winnable-deal solver are
+  verified under unlimited recycling, so introducing a hard pass limit would
+  invalidate both. Locked in by the
+  `draw_one_recycling_is_unlimited_by_design` test in
+  `solitaire_core/src/game_state.rs`. (Decision record: Gitea issue #117.)
+
 ### `solitaire_sync`
 **Dependencies:** `serde`, `serde_json`, `uuid`, `chrono` only.