chore(core): stage 1 contracts — dialog, API schemas + fixtures, integrations, monitoring, modules

Freeze interfaces between lanes A (bot), B (backend), C (dashboard) so three developers work in
parallel without touching each other's files: dialog Event/Reply + engine registry with echo stub,
integration protocols with in-memory defaults, MonitoringService with noop stub, /api/v1 schemas
with fixture-backed routes, frozen main.py wiring, config/modules.yaml + due_scales(), DAR-5,
tzdata, Andrey trajectory, lanes in WORKFLOW, ADR-010.

Refs #34

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

app/llm/gateway.py

@@ -168,9 +168,7 @@ def get_gateway() -> LLMGateway:
 
 
 # Module-level shortcuts, so callers can `from app.llm import gateway; await gateway.extract_item(...)`.
-async def extract_item(
-    scale_item_id: str, item_text: str, max_score: int, answer: ScrubbedText
-) -> ItemScore | None:
+async def extract_item(scale_item_id: str, item_text: str, max_score: int, answer: ScrubbedText) -> ItemScore | None:
     return await get_gateway().extract_item(scale_item_id, item_text, max_score, answer)