fix: improve blockchain node RPC responses and database path consistency

- Add transaction data to RPC responses (get_block, get_blocks_range)
- Fix import_block to handle transactions parameter
- Change database paths to absolute paths for consistency
- Make dev_heartbeat.py executable

apps/coordinator-api/scripts/migrate_complete.py

@@ -8,7 +8,7 @@ import json
 from decimal import Decimal
 
 # Database configurations
-SQLITE_DB = "coordinator.db"
+SQLITE_DB = "/opt/aitbc/data/coordinator.db"
 PG_CONFIG = {
     "host": "localhost",
     "database": "aitbc_coordinator",

apps/coordinator-api/scripts/migrate_to_postgresql.py

@@ -16,7 +16,7 @@ from decimal import Decimal
 import json
 
 # Database configurations
-SQLITE_DB = "coordinator.db"
+SQLITE_DB = "/opt/aitbc/data/coordinator.db"
 PG_CONFIG = {
     "host": "localhost",
     "database": "aitbc_coordinator",