docs: verify and update Epic 1 story statuses to Completed

- Verified all acceptance criteria for Stories 1.1-1.6
- Updated Status fields from Pending to Completed
- Marked all acceptance criteria checkboxes as completed
- All stories in Epic 1 are now fully implemented and verified

docs/content/stories/epic1/1.2-database-layer.md

@@ -4,7 +4,7 @@
 - **Story ID**: 1.2
 - **Title**: Database Layer with Ent ORM
 - **Epic**: 1 - Core Kernel & Infrastructure
-- **Status**: Pending
+- **Status**: Completed
 - **Priority**: High
 - **Estimated Time**: 6-8 hours
 - **Dependencies**: 1.1
@@ -97,15 +97,15 @@ Define core entities:
    - Test connection
 
 ## Acceptance Criteria
-- [ ] Ent schema compiles and generates code successfully
-- [ ] Database client connects to PostgreSQL
-- [ ] Core entities can be created and queried
-- [ ] Migrations run successfully on startup
-- [ ] Connection pooling is configured correctly
-- [ ] Database health check works
-- [ ] All entities have proper indexes and relationships
-- [ ] Database client is injectable via DI
-- [ ] Connections are closed gracefully on shutdown
+- [x] Ent schema compiles and generates code successfully
+- [x] Database client connects to PostgreSQL
+- [x] Core entities can be created and queried
+- [x] Migrations run successfully on startup
+- [x] Connection pooling is configured correctly
+- [x] Database health check works
+- [x] All entities have proper indexes and relationships
+- [x] Database client is injectable via DI
+- [x] Connections are closed gracefully on shutdown
 
 ## Related ADRs
 - [ADR-0013: Database ORM](../../adr/0013-database-orm.md)