feat: extract shared infrastructure from shared_lib

Phase 1-3 of decoupling plan:
- Shared DB, models, infrastructure, browser, config, utils
- Event infrastructure (domain_events outbox, bus, processor)
- Structured logging
- Generic container concept (container_type/container_id)
- Alembic migrations for all schema changes

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

browser/app/utils/__init__.py

@@ -0,0 +1,12 @@
+from .parse import (
+  parse_time,
+  parse_cost,
+  parse_dt
+)
+from .utils import (
+  current_route_relative_path,
+  current_url_without_page,
+  vary,
+)
+
+from .utc import utcnow