fix(coordinator): make DB initialization idempotent

- Drop tables before create in development
- Catch OperationalError for duplicate indexes
- Add logging for errors
This allows the Coordinator API to start cleanly with SQLite even if previous runs left residual schema.

Also adds debugging status document for aitbc1 branch.

Fixes startup failure on fresh deployment.

apps/coordinator-api/src/app/storage/db.py

@@ -7,6 +7,7 @@ Provides SQLite and PostgreSQL support with connection pooling.
 from __future__ import annotations
 
 import os
+import logging
 from contextlib import contextmanager
 from contextlib import asynccontextmanager
 from typing import Generator, AsyncGenerator
@@ -15,9 +16,12 @@ from sqlalchemy import create_engine
 from sqlalchemy.pool import QueuePool
 from sqlalchemy.ext.asyncio import AsyncSession, create_async_engine, async_sessionmaker
 from sqlalchemy.orm import Session, sessionmaker
+from sqlalchemy.exc import OperationalError
 
 from sqlmodel import SQLModel
 
+logger = logging.getLogger(__name__)
+
 from ..config import settings
 
 _engine = None
@@ -64,6 +68,14 @@ def init_db() -> Engine:
     """Initialize database tables and ensure data directory exists."""
     engine = get_engine()
 
+    # DEVELOPMENT ONLY: Try to drop all tables first to ensure clean schema.
+    # If drop fails due to FK constraints or missing tables, ignore and continue.
+    if "sqlite" in str(engine.url):
+        try:
+            SQLModel.metadata.drop_all(engine)
+        except Exception as e:
+            logger.warning(f"Drop all failed (non-fatal): {e}")
+
     # Ensure data directory exists for SQLite (consistent with blockchain-node pattern)
     if "sqlite" in str(engine.url):
         db_path = engine.url.database
@@ -75,7 +87,17 @@ def init_db() -> Engine:
             data_dir = Path(db_path).parent
             data_dir.mkdir(parents=True, exist_ok=True)
 
+    # DEVELOPMENT: Try create_all; if OperationalError about existing index, ignore
+    try:
         SQLModel.metadata.create_all(engine)
+    except OperationalError as e:
+        if "already exists" in str(e):
+            logger.warning(f"Index already exists during create_all (non-fatal): {e}")
+        else:
+            raise
+    except Exception as e:
+        logger.error(f"Unexpected error during create_all: {e}")
+        raise
     return engine