docs: Clarify database schema update process in PROJECT_GUIDELINES

- Add explicit note that this is pre-production (no deployments)
- Document two options for updating local databases after schema changes
- Option 1: Recreate database (recommended, loses data)
- Option 2: Manual SQL migration (preserves data)
- Explicitly state: DO NOT create migration files
- Update checklist to include database update step
- Cross-reference from full-stack tasks section

Clarifies the 'no migration needed' philosophy for future developers

PROJECT_GUIDELINES.md

@@ -89,6 +89,7 @@ VERIFY → Compile successfully
 ### When Working on Full-Stack Tasks
 - Backend changes are allowed when explicitly part of the task
 - Still follow all database protocols (atomic changes, validation, etc.)
+- **If modifying database schema:** Update local database after schema.sql changes (see Database Operations section)
 - Still use Podman for all builds
 - Still include Bruno tests for API changes
 
@@ -99,7 +100,15 @@ VERIFY → Compile successfully
 ### Database Operations (Full-Stack Tasks Only)
 - ✅ Follow **pgx v5 standards** for all database operations
 - ✅ Treat schema changes as **ATOMIC** - complete success or complete rejection
-- ✅ When schema changes occur: delete database and rebuild with clean Podman cache
+- ✅ **⚠️ CRITICAL: This is a pre-production application (NO production deployments exist)**
+  - When `database/schema/schema.sql` is updated, local databases must be updated
+  - **Option 1 (Recommended):** Recreate database with fresh schema:
+    ```bash
+    podman compose down -v  # Delete volumes (WARNING: loses all data)
+    podman compose up -d    # Start fresh with new schema
+    ```
+  - **Option 2:** Manually apply schema changes to existing database using psql
+  - **DO NOT create migration files** - no legacy schema support needed
 - ✅ Use **pre-change checklist**: read schema → identify columns → plan changes → verify → read back
 - ✅ **Post-change validation**: ensure schema.sql, models.go, and queries.sql are in sync
 
@@ -297,6 +306,17 @@ git checkout -- internal/handlers/auth.go
 - [ ] Immediately verify by reading back modified sections
 - [ ] Confirm ALL expected columns are present
 - [ ] Verify schema.sql, models.go, and queries.sql are in sync
+- [ ] **Update local database** (choose ONE):
+  - [ ] **Option 1 - Recreate database** (recommended, loses data):
+    ```bash
+    podman compose down -v  # Delete all volumes
+    podman compose up -d    # Start with fresh schema
+    ```
+  - [ ] **Option 2 - Manual SQL migration** (preserves data):
+    ```bash
+    podman exec bookhoard_db psql -U postgres -d bookhoard -c "YOUR SQL HERE"
+    ```
+- [ ] Verify database has new schema (check column types, indexes, etc.)
 
 ### After API Changes
 - [ ] Create/update Bruno DSL .bru requests