feat(bot): dialog engine — scrub → safety → FSM → monitoring, consent, age gate, crisis

- Engine.handle registered via register_engine; lexicon-first safety (no LLM on ACUTE),
  fixed crisis script once per open crisis, POSSIBLE → C-SSRS screen
- FSM registry (@state/@on_enter/@trigger) with auto-loaded flows; core flow:
  new → consent → age_gate → module onboarding → idle, crisis, consent_revoked
- reusable scale session (buttons, extract_item + clarify, item 9 / C-SSRS buttons-only,
  crisis flags), execution of monitoring dialog actions, texts in config/texts/dialog.yaml

Refs #10

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

app/dialog/actions.py

@@ -0,0 +1,73 @@
+"""Execution of *dialog* actions returned by `MonitoringService.after_data_change()` (ADR-007).
+
+The rules (lane B, `config/rules.yaml`) decide WHAT happens; this module only turns an already chosen action
+into replies. `alert` / `enhanced_monitoring` are handled by lane B itself (persisted + doctor notified), so they
+are ignored here. While a crisis is open only crisis-relevant actions (crisis, safety plan, risk screen) reach
+the patient: no medication tips or visit offers in the middle of a crisis.
+"""
+
+from collections.abc import Iterable
+from typing import Any
+
+from app.core.rules import Action
+from app.db.clinical import SafetyPlan
+from app.dialog.contracts import Button, Reply
+from app.dialog.crisis import crisis_open, open_crisis
+from app.dialog.fsm import Ctx, Step
+from app.dialog.scale_session import active_scale, add_pending
+
+# med_info topic → phrase intent of `config/texts/phrases.yaml` (the LLM only rephrases the template).
+_MED_INFO_INTENTS = {"delayed_effect": "quit_intent", "alcohol_interaction": "alcohol_info", "nausea": "nausea_info"}
+_CRISIS_SAFE = {"crisis", "show_safety_plan", "schedule_scale"}
+
+
+def _plan_line(step: Any) -> str:
+    if isinstance(step, dict):
+        return ": ".join(str(v) for v in step.values() if v)
+    return str(step)
+
+
+async def safety_plan_reply(ctx: Ctx, block: str | None = None) -> Reply:
+    """The plan composed with the doctor (`safety_plans`), or the Stanley–Brown template from config."""
+    row = await ctx.session.get(SafetyPlan, ctx.token)
+    steps = [_plan_line(s) for s in row.steps] if row is not None and row.steps else ctx.texts.safety_plan.template
+    lines = [ctx.texts.safety_plan.title, *(f"{i}. {s}" for i, s in enumerate(steps, 1))]
+    if block == "means_restriction":
+        lines += ["", ctx.texts.safety_plan.means_restriction]
+    return Reply(text="\n".join(lines), kind="safety_plan")
+
+
+async def execute(ctx: Ctx, actions: Iterable[Action]) -> Step:
+    step = Step()
+    shown_plan = False
+    for action in actions:
+        if crisis_open({**ctx.data, **step.data}) and action.type not in _CRISIS_SAFE:
+            continue
+        if action.type == "crisis":
+            if not crisis_open({**ctx.data, **step.data}):
+                step = step.then(open_crisis(ctx, categories=[], source=f"rule:{action.code}"))
+        elif action.type == "show_safety_plan" and not shown_plan:
+            shown_plan = True
+            step = step.then(Step(replies=[await safety_plan_reply(ctx, action.params.get("block"))]))
+        elif action.type == "schedule_scale" and action.params.get("scale"):
+            scale_id = str(action.params["scale"])
+            if active_scale(step.next_state or ctx.state) == scale_id:
+                continue  # already being asked
+            data = {**ctx.data, **step.data}
+            pending = add_pending(data, scale_id, bool(action.params.get("scheduled", False)))
+            step = step.then(Step(data={"pending_scales": pending}))
+        elif action.type == "med_info":
+            intent = _MED_INFO_INTENTS.get(str(action.params.get("topic")), "default")
+            text = await ctx.gateway.phrase(intent, {})
+            step = step.then(Step(replies=[Reply(text=text, kind="info")]))
+        elif action.type == "suggest_visit":
+            text = await ctx.gateway.phrase("book_visit_offer", {})
+            button = Button(label=ctx.texts.visit.button, data="menu:visit")
+            step = step.then(Step(replies=[Reply(text=text, buttons=[[button]], kind="info")]))
+        elif action.type == "reach_out":
+            topic = str(action.params.get("topic", "default"))
+            texts = ctx.texts.reach_out
+            text = {"silence": texts.silence, "missed_doses": texts.missed_doses}.get(topic, texts.default)
+            step = step.then(Step(replies=[Reply(text=text)]))
+        # alert / enhanced_monitoring: lane B persists and notifies; nothing to say to the patient.
+    return step