feat: add transaction hash search to blockchain explorer and cleanup settlement storage

Blockchain Explorer:
- Add transaction hash search support (64-char hex pattern validation)
- Fetch and display transaction details in modal (hash, type, from/to, amount, fee, block)
- Fix regex escape sequence in block height validation
- Update search placeholder text to mention both search types
- Add blank lines between function definitions for PEP 8 compliance

Settlement Storage:
- Add timedelta import for future

apps/coordinator-api/src/app/config.py

@@ -4,115 +4,137 @@ Unified configuration for AITBC Coordinator API
 Provides environment-based adapter selection and consolidated settings.
 """
 
+import os
 from pydantic_settings import BaseSettings, SettingsConfigDict
 from typing import List, Optional
 from pathlib import Path
-import os
 
 
 class DatabaseConfig(BaseSettings):
     """Database configuration with adapter selection."""
+
     adapter: str = "sqlite"  # sqlite, postgresql
     url: Optional[str] = None
     pool_size: int = 10
     max_overflow: int = 20
     pool_pre_ping: bool = True
-    
+
     @property
     def effective_url(self) -> str:
         """Get the effective database URL."""
         if self.url:
             return self.url
-        
+
         # Default SQLite path
         if self.adapter == "sqlite":
             return "sqlite:///./coordinator.db"
-        
+
         # Default PostgreSQL connection string
         return f"{self.adapter}://localhost:5432/coordinator"
-    
+
     model_config = SettingsConfigDict(
-        env_file=".env",
-        env_file_encoding="utf-8",
-        case_sensitive=False,
-        extra="allow"
+        env_file=".env", env_file_encoding="utf-8", case_sensitive=False, extra="allow"
     )
 
 
 class Settings(BaseSettings):
     """Unified application settings with environment-based configuration."""
+
     model_config = SettingsConfigDict(
-        env_file=".env",
-        env_file_encoding="utf-8",
-        case_sensitive=False,
-        extra="allow"
+        env_file=".env", env_file_encoding="utf-8", case_sensitive=False, extra="allow"
     )
 
     # Environment
     app_env: str = "dev"
     app_host: str = "127.0.0.1"
     app_port: int = 8011
-    
+    audit_log_dir: str = "/var/log/aitbc/audit"
+
     # Database
     database: DatabaseConfig = DatabaseConfig()
-    
+
     # API Keys
     client_api_keys: List[str] = []
     miner_api_keys: List[str] = []
     admin_api_keys: List[str] = []
-    
+
     # Security
     hmac_secret: Optional[str] = None
     jwt_secret: Optional[str] = None
     jwt_algorithm: str = "HS256"
     jwt_expiration_hours: int = 24
-    
+
     # CORS
     allow_origins: List[str] = [
         "http://localhost:3000",
         "http://localhost:8080",
         "http://localhost:8000",
-        "http://localhost:8011"
+        "http://localhost:8011",
     ]
-    
+
     # Job Configuration
     job_ttl_seconds: int = 900
     heartbeat_interval_seconds: int = 10
     heartbeat_timeout_seconds: int = 30
-    
+
     # Rate Limiting
     rate_limit_requests: int = 60
     rate_limit_window_seconds: int = 60
-    
+
     # Receipt Signing
     receipt_signing_key_hex: Optional[str] = None
     receipt_attestation_key_hex: Optional[str] = None
-    
+
     # Logging
     log_level: str = "INFO"
     log_format: str = "json"  # json or text
-    
+
     # Mempool
     mempool_backend: str = "database"  # database, memory
-    
+
+    # Blockchain RPC
+    blockchain_rpc_url: str = "http://localhost:8082"
+
+    # Test Configuration
+    test_mode: bool = False
+    test_database_url: Optional[str] = None
+
     def validate_secrets(self) -> None:
         """Validate that all required secrets are provided."""
         if self.app_env == "production":
             if not self.jwt_secret:
-                raise ValueError("JWT_SECRET environment variable is required in production")
+                raise ValueError(
+                    "JWT_SECRET environment variable is required in production"
+                )
             if self.jwt_secret == "change-me-in-production":
                 raise ValueError("JWT_SECRET must be changed from default value")
-    
+
     @property
     def database_url(self) -> str:
         """Get the database URL (backward compatibility)."""
+        # Use test database if in test mode and test_database_url is set
+        if self.test_mode and self.test_database_url:
+            return self.test_database_url
         if self.database.url:
             return self.database.url
         # Default SQLite path for backward compatibility
         return f"sqlite:///./aitbc_coordinator.db"
 
+    @database_url.setter
+    def database_url(self, value: str):
+        """Allow setting database URL for tests"""
+        if not self.test_mode:
+            raise RuntimeError("Cannot set database_url outside of test mode")
+        self.test_database_url = value
+
 
 settings = Settings()
 
+# Enable test mode if environment variable is set
+if os.getenv("TEST_MODE") == "true":
+    settings.test_mode = True
+    if os.getenv("TEST_DATABASE_URL"):
+        settings.test_database_url = os.getenv("TEST_DATABASE_URL")
+
 # Validate secrets on import
 settings.validate_secrets()