feat(bot): answer treatment questions from the clinical-guideline knowledge base

- menu button «Вопрос о лечении» -> kb.question -> rag.answer (KR quote + source)
  or «уточните у врача»; dose questions get a fixed doctor redirect
- free text in idle that looks like a question (no check-in signals, not a drug
  question) -> knowledge base; no answer -> the usual support phrase
- routing order unchanged: consent/safety first, side effects/quit/alcohol -> check-in,
  own drug -> med_qa (instruction only, SPEC §7 p.5)
- question cues, small talk and texts in config/texts/knowledge.yaml; scrub placeholders
  before "что такое X" no longer hide the definition question

Refs #64

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

app/dialog/flows/veteran_daily.py

@@ -47,6 +47,7 @@ from app.db import repo
 from app.dialog.contracts import Button, Event, Reply
 from app.dialog.flows import intake
 from app.dialog.flows.core import menu_reply
+from app.dialog.flows.knowledge import knowledge_answer, looks_like_question
 from app.dialog.flows.meds import (
     answer_question,
     checkin_of,
@@ -423,11 +424,13 @@ async def _visit(ctx: Ctx, event: Event) -> Step:
 @trigger("text:idle", replace=True)
 async def _idle_text(ctx: Ctx, event: Event) -> Step:
     """Free text outside the check-in: drug question → instruction excerpt; side effects / quit intent / alcohol
-    → today's check-in (the rules react); otherwise the neutral support phrase with the menu."""
+    → today's check-in (the rules react); another question → clinical guidelines (knowledge base); otherwise
+    the neutral support phrase with the menu."""
     assert ctx.text is not None
     facts = await ctx.gateway.extract_checkin(ctx.text)
     if facts is None:
-        return Step(replies=[menu_reply(ctx, await ctx.gateway.phrase("support"))])
+        text = await knowledge_answer(ctx, explicit=False) if looks_like_question(ctx.text) else None
+        return Step(replies=[menu_reply(ctx, text or await ctx.gateway.phrase("support"))])
     fields: dict[str, Any] = {}
     if facts.quit_intent:
         fields["quit_intent"] = True
@@ -445,6 +448,8 @@ async def _idle_text(ctx: Ctx, event: Event) -> Step:
         await save_checkin(ctx, **fields)
     if text is None and facts.med_question and not facts.quit_intent:
         text = await answer_question(ctx, await current_prescription(ctx))
+    if text is None and not fields and looks_like_question(ctx.text):
+        text = await knowledge_answer(ctx, explicit=False)  # general question → clinical guidelines (#64)
     if text is None:
         text = await ctx.gateway.phrase("support")
     return Step(replies=[menu_reply(ctx, text)], notify_monitoring=bool(fields or facts.side_effects))