fix: merge main into feature branch - resolve all 18 conflicts cleanly

Merges origin/main (v0.155.0) into the classification feature branch,
resolving all 18 conflicted files by accepting main's version and
re-applying only classification-specific additions:

- Renumber migration from 037 to 038 (chains from 037_user_sessions)
- Re-add ClassificationRuleModel to models.py, env.py, conftest.py
- Re-add classification_rules_router to api/__init__.py
- All session management, QR auth, and devices code preserved from main

Migration chain validated. 62 classification tests pass.

Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>

app/api/__init__.py

@@ -34,11 +34,13 @@ from app.api.pipelines import router as pipelines_router
 from app.api.plans import router as plans_router
 from app.api.process import router as process_router
 from app.api.profile import router as profile_router
+from app.api.qr_auth import router as qr_auth_router
 from app.api.queue import router as queue_router
 from app.api.routing_rules import router as routing_rules_router
 from app.api.saved_searches import router as saved_searches_router
 from app.api.scheduled_jobs import router as scheduled_jobs_router
 from app.api.search import router as search_router
+from app.api.sessions import router as sessions_router
 from app.api.settings import router as settings_router
 from app.api.shared_links import public_router as shared_links_public_router
 from app.api.shared_links import router as shared_links_router
@@ -98,6 +100,8 @@ router.include_router(scheduled_jobs_router)
 router.include_router(audit_logs_router)
 router.include_router(i18n_router)
 router.include_router(mobile_router)
+router.include_router(sessions_router)
+router.include_router(qr_auth_router)
 router.include_router(compliance_router)
 router.include_router(system_reset_router)
 router.include_router(translation_router)