refactor(simulation): PR #137 review — audit override + regression tests + docs

Addresses Tyre, Hoshe, and lead review comments on PR #137:

- **Audit doc amendment** (Tyre E1 / Hoshe H1 / Lead): add "Lead override
  (2026-04-21)" section at top of docs/architecture/sprint-37-878-audit.md.
  Rewrites the conclusion to "DECISION: STRIP" with the cascade-based
  rationale. Preserves the original audit body as the pre-override record.

- **Regression tests** (Lead 2a-2b / Hoshe H2 / H3): add POSITIVE
  assertions of the new uniform behavior so silent reintroduction fails.
  - `phase2_container_verb_labels_uniform_regardless_of_player_state` —
    two trials (empty KG, POI-bearing KG) assert container verb labels
    equal Phase-1 defaults.
  - `monologue_pool_selection_uniform_no_archetype_key` — two observers
    with divergent MonologueState both draw from OBSERVE_NPC_LINES.

- **Decision record amendments** (Lead 3 / Tyre S2): D-032, D-035, and
  D-057 amended with Phase 6 deferral wording. "Retired pending Phase 6,
  not deferred with scaffolding." Reintroduction gate: a confirmed
  Phase 6 character-model design.

- **types.rs doc fixes** (Tyre S1 / Hoshe H5): StartupMessage protocol-
  flow comment updated to reflect no-version handshake (D-192).
  ObserverSnapshot version-history block grows a "Sprint 37 wire-format
  shifts" section documenting D-192 + #878 schema drops.

- **observer/tests.rs:944 comment** (Hoshe H6): rewritten to cite
  cascade rationale instead of the stale D-032-SUPERSEDED premise.

- **tests/run-atlas-determinism exit** (Hoshe H7): exit 0 when EXIT_CODE=2
  (venv/DB missing = skip, not fail). Preserves skip semantics for
  tests/run-all on machines without the Python venv.

Follow-up tickets filed:
- #895 (server, low): expand check-systems-db-stamp GENERATOR_SOURCES
  to cover gemma_naming.py + naming_core.py (Tyre S3).
- #896 (planning, low): add CLAUDE.md carveout for server wiki writes
  closing coverage gates (Tyre S4 / Hoshe H8).

H4 investigation: v01_integration_playthrough.rs was not the only E2E
handshake→tick→snapshot test; coverage preserved by bridge_ipc.rs,
bridge_tcp.rs, and game_loop.rs (the latter is pre-existing-broken
per #885). No replacement test needed.

1142/1142 lib tests pass. cargo clippy -- -D warnings clean.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tests/run-atlas-determinism

@@ -133,4 +133,7 @@ fi
 
 printf '{"suite":"atlas-determinism","total":%d,"passed":%d,"failed":%d,"duration_ms":%d}\n' \
     "$TOTAL" "$PASSED" "$FAILED" "$DURATION_MS"
-exit $EXIT_CODE
+
+# Exit code 2 = venv/DB missing → treated as skip, not failure (exit 0 for run-all).
+# Exit code 1 = determinism failure → exit 1 to fail CI.
+[[ $EXIT_CODE -eq 2 ]] && exit 0 || exit $EXIT_CODE