feat: add Phase 4 Logging & Tracking — inline set logging, history views

Add workout logging so users can track sets, reps, weight, and a
"felt easy?" toggle inline from the workout day view via HTMX.
Sessions auto-create on first log. History page shows past sessions
with detailed per-exercise breakdowns.

New services: WorkoutSessionService, LogService
New routes: POST /log, /log/{id}/edit, /log/{id}/delete, GET /history, /history/{id}
New templates: log_form, log_entry, session_card, log_history, session_detail
Modified: exercise_card (inline logging), nav (History link), workouts route (session context)

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

tests/test_workout_session_service.py

@@ -0,0 +1,83 @@
+"""Tests for the WorkoutSessionService class."""
+
+from datetime import date
+
+from sqlmodel import SQLModel, Session, create_engine
+
+from app.models.user import User
+from app.models.workout_day import WorkoutDay
+from app.models.workout_session import WorkoutSession
+from app.services.workout_session_service import WorkoutSessionService
+
+
+class TestWorkoutSessionService:
+    """Tests for workout session CRUD operations."""
+
+    def _setup(self):
+        """Create an in-memory DB with prerequisite data."""
+        engine = create_engine("sqlite:///:memory:")
+        SQLModel.metadata.create_all(engine)
+        session = Session(engine)
+
+        user = User(username="phil", password_hash="h", display_name="Phillip")
+        day = WorkoutDay(name="Push", day_number=1, description="Push day")
+        session.add_all([user, day])
+        session.commit()
+        session.refresh(user)
+        session.refresh(day)
+
+        service = WorkoutSessionService(session)
+        return session, service, user, day
+
+    def test_get_or_create_session_creates_new(self) -> None:
+        """get_or_create_session should create a new session if none exists."""
+        session, service, user, day = self._setup()
+        ws = service.get_or_create_session(
+            user_id=user.id,
+            workout_day_id=day.id,
+            session_date=date.today(),
+        )
+        assert ws.id is not None
+        assert ws.user_id == user.id
+        assert ws.workout_day_id == day.id
+        session.close()
+
+    def test_get_or_create_session_returns_existing(self) -> None:
+        """get_or_create_session should return existing session for same day."""
+        session, service, user, day = self._setup()
+        ws1 = service.get_or_create_session(user.id, day.id, date.today())
+        ws2 = service.get_or_create_session(user.id, day.id, date.today())
+        assert ws1.id == ws2.id
+        session.close()
+
+    def test_list_sessions_for_user(self) -> None:
+        """list_sessions should return all sessions for a user."""
+        session, service, user, day = self._setup()
+        service.get_or_create_session(user.id, day.id, date.today())
+        sessions = service.list_sessions(user_id=user.id)
+        assert len(sessions) == 1
+        session.close()
+
+    def test_list_sessions_empty(self) -> None:
+        """list_sessions should return empty list for user with no sessions."""
+        session, service, user, day = self._setup()
+        sessions = service.list_sessions(user_id=user.id)
+        assert len(sessions) == 0
+        session.close()
+
+    def test_get_session_by_id(self) -> None:
+        """get_session_by_id should return the correct session."""
+        session, service, user, day = self._setup()
+        ws = service.get_or_create_session(user.id, day.id, date.today())
+        found = service.get_session_by_id(ws.id)
+        assert found is not None
+        assert found.id == ws.id
+        session.close()
+
+    def test_update_session_notes(self) -> None:
+        """update_session should allow updating notes."""
+        session, service, user, day = self._setup()
+        ws = service.get_or_create_session(user.id, day.id, date.today())
+        updated = service.update_session(ws.id, notes="Great workout!")
+        assert updated.notes == "Great workout!"
+        session.close()