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>

app/main.py

@@ -24,9 +24,11 @@ from app.database import get_engine, get_db_session
 from app.logging_config import setup_logging
 from app.routes.auth import router as auth_router
 from app.routes.exercises import router as exercises_router
+from app.routes.history import router as history_router
 from app.routes.health import router as health_router
 from app.routes.pages import router as pages_router
 from app.routes.profiles import router as profiles_router
+from app.routes.logging import router as logging_router
 from app.routes.workouts import router as workouts_router
 from app.services.seed_service import SeedService
 from app.services.auth_service import AuthService
@@ -104,6 +106,8 @@ def create_app() -> FastAPI:
     app.include_router(auth_router)
     app.include_router(exercises_router)
     app.include_router(health_router)
+    app.include_router(history_router)
+    app.include_router(logging_router)
     app.include_router(pages_router)
     app.include_router(profiles_router)
     app.include_router(workouts_router)