feat: Add PostgreSQL fields and workflow for form without files

Database changes:
- Add unified_id, contact_id, phone columns to clpr_claims table
- Create indexes for fast lookup by these fields
- Migrate existing data from payload to new columns
- SQL migration: docs/SQL_ALTER_CLPR_CLAIMS_ADD_FIELDS.sql

SQL improvements:
- Simplify claimsave query: remove complex claim_lookup logic
- Use UPSERT (INSERT ON CONFLICT) with known claim_id
- Always return claim (fix NULL issue)
- Store unified_id, contact_id, phone directly in table columns
- SQL: docs/SQL_CLAIMSAVE_UPSERT_SIMPLE.sql

Workflow enhancements:
- Add branch for form submissions WITHOUT files
- Create 6 new nodes: extract, prepare, save, redis, respond
- Separate flow for has_files=false in IF node
- Instructions: docs/N8N_FORM_GET_NO_FILES_INSTRUCTIONS.md
- Node config: docs/N8N_FORM_GET_NO_FILES_BRANCH.json

Migration stats:
- Total claims: 81
- With unified_id: 77
- Migrated from payload: 2

Next steps:
1. Add 6 nodes to n8n workflow form_get (ID: 8ZVMTsuH7Cmw7snw)
2. Connect TRUE branch of IF node to extract_webhook_data_no_files
3. Test form submission without files
4. Verify PostgreSQL save and Redis event

docs/DATABASE_SCHEMA.md

@@ -181,3 +181,4 @@ clpr_user_accounts (channel='telegram', channel_user_id=telegram_id)
 clpr_users (id)
 ```
 
+