Phase 3: coaching preferences + weekly check-in engine

Add coaching preferences (auto-derived from the profile, user-overridable) and
a periodic check-in engine that quotes the person's own words and asks whether
their direction still feels valid — mirror, not compass.

- Preferences are deterministic: a documented triad mapping (gut → direct/
  higher-friction, heart → warm/drift-sensitive, head → reflective/question-led)
  produces defaults for the six fields (coaching_frequency, coaching_style,
  misalignment_threshold, friction_tolerance, prefer_questions_over_directives,
  time_of_day_preference). PUT overrides; regenerate re-derives.
- CheckinCoach (app/services/coaching.py): Anthropic-backed; writes a check-in
  that quotes the person's goals back and asks if the direction still holds.
- Endpoints (app/routers/coaching.py): GET/PUT/regenerate preferences;
  GET/POST checkins; respond (records still_valid); admin POST /run is the
  weekly batch (due = cadence elapsed + locked profile), intended for a cron.
- Models + migration 005: coaching_preferences (per user) and coaching_checkin.
- Frontend: coaching.html (preferences form + check-in feed); linked from
  profile.html.

Tests: 68 passing (added deterministic-preference unit tests and coaching
endpoint/batch tests; run in-container). README updated for Phase 3.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

app/models.py

@@ -188,3 +188,61 @@ class ProfileRevision(Base):
     fields_json: Mapped[str] = mapped_column(Text, nullable=False)
     note: Mapped[Optional[str]] = mapped_column(Text, nullable=True)
     created_at: Mapped[datetime] = mapped_column(DateTime, nullable=False)
+
+
+class CoachingPreferences(Base):
+    """Phase 3: how this person wants to be coached. Auto-generated from their
+    Enneagram/Ikigai profile, then overridable. One row per user."""
+
+    __tablename__ = "coaching_preferences"
+
+    id: Mapped[str] = mapped_column(String, primary_key=True)
+    user_id: Mapped[str] = mapped_column(
+        String, ForeignKey("users.id"), unique=True, nullable=False, index=True
+    )
+    # The profile the defaults were derived from (provenance).
+    profile_id: Mapped[Optional[str]] = mapped_column(
+        String, ForeignKey("discovery_profile.id"), nullable=True
+    )
+
+    coaching_frequency: Mapped[str] = mapped_column(String, nullable=False)
+    coaching_style: Mapped[str] = mapped_column(String, nullable=False)
+    misalignment_threshold: Mapped[str] = mapped_column(String, nullable=False)
+    friction_tolerance: Mapped[str] = mapped_column(String, nullable=False)
+    prefer_questions_over_directives: Mapped[bool] = mapped_column(
+        Boolean, nullable=False, default=True
+    )
+    time_of_day_preference: Mapped[str] = mapped_column(String, nullable=False)
+
+    # True while still using auto-derived defaults; False once the user edits.
+    auto_generated: Mapped[bool] = mapped_column(
+        Boolean, nullable=False, default=True
+    )
+    created_at: Mapped[datetime] = mapped_column(DateTime, nullable=False)
+    updated_at: Mapped[datetime] = mapped_column(DateTime, nullable=False)
+
+
+class CoachingCheckin(Base):
+    """Phase 3: a periodic coaching check-in. The body quotes the person's own
+    words and asks whether their stated direction still feels valid (mirror,
+    not compass). The person's answer is recorded in still_valid."""
+
+    __tablename__ = "coaching_checkin"
+
+    id: Mapped[str] = mapped_column(String, primary_key=True)
+    user_id: Mapped[str] = mapped_column(
+        String, ForeignKey("users.id"), nullable=False, index=True
+    )
+    profile_id: Mapped[str] = mapped_column(
+        String, ForeignKey("discovery_profile.id"), nullable=False
+    )
+    body: Mapped[str] = mapped_column(Text, nullable=False)
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime, nullable=False, index=True
+    )
+    # The person's self-assessment: is their direction still valid?
+    still_valid: Mapped[Optional[bool]] = mapped_column(Boolean, nullable=True)
+    response_note: Mapped[Optional[str]] = mapped_column(Text, nullable=True)
+    acknowledged_at: Mapped[Optional[datetime]] = mapped_column(
+        DateTime, nullable=True
+    )