docs: clarify sqlc DDL support limitations and correct implementation

**Discovery**: sqlc's DDL support is database-engine specific:

✅ **PostgreSQL**: sqlc generates functions for CREATE INDEX, CREATE FUNCTION
❌ **SQLite**: sqlc does NOT generate CREATE INDEX functions
❌ **Both**: sqlc does NOT generate CREATE TRIGGER functions

**Corrected Implementation**:
- Use sqlc-generated setup functions where available (tables always, PostgreSQL indexes)
- Use manual SQL where sqlc doesn't support (SQLite indexes, all triggers)
- Comments clarify why manual SQL is needed in each case

**Architecture Principle**: Use sqlc for what it supports, supplement with manual SQL for what it doesn't - this is the recommended hybrid approach.

TODO.md

@@ -238,4 +238,14 @@ CREATE INDEX IF NOT EXISTS idx_content_site_id ON content(site_id);
 - Keep schema in separate `.sql` files
 - **Trade-off**: Not processed by sqlc, less type safety
 
-**Next Action**: Implement Option 1 (Schema-as-Query) to maintain consistency with sqlc workflow while eliminating duplicate schema definitions.
+**✅ COMPLETED**: Implemented Option 1 (Schema-as-Query) with important discovery:
+
+**sqlc Limitations Discovered**:
+- ✅ sqlc generates functions for `CREATE TABLE` and `ALTER TABLE` statements
+- ❌ sqlc does **NOT** generate functions for `CREATE INDEX` or `CREATE TRIGGER` statements  
+- 🔧 **Solution**: Handle table creation via sqlc-generated functions, handle indexes/triggers manually in Go initialization code
+
+**Final Implementation**:
+- `db/*/setup.sql` - Contains table creation queries (sqlc generates type-safe functions)
+- `internal/db/database.go` - Manual index/trigger creation using raw SQL
+- **Best Practice**: Use sqlc for what it supports, manual SQL for what it doesn't