feat(migration): implement interactive mapping resolution workflow

- Add SQLite database integration for environments and mappings
- Update TaskManager to support pausing tasks (AWAITING_MAPPING)
- Modify MigrationPlugin to detect missing mappings and wait for resolution
- Add frontend UI for handling missing mappings interactively
- Create dedicated migration routes and API endpoints
- Update .gitignore and project documentation

backend/src/api/routes/environments.py

@@ -0,0 +1,75 @@
+# [DEF:backend.src.api.routes.environments:Module]
+#
+# @SEMANTICS: api, environments, superset, databases
+# @PURPOSE:   API endpoints for listing environments and their databases.
+# @LAYER:     API
+# @RELATION:  DEPENDS_ON -> backend.src.dependencies
+# @RELATION:  DEPENDS_ON -> backend.src.core.superset_client
+#
+# @INVARIANT: Environment IDs must exist in the configuration.
+
+# [SECTION: IMPORTS]
+from fastapi import APIRouter, Depends, HTTPException
+from typing import List, Dict, Optional
+from backend.src.dependencies import get_config_manager
+from backend.src.core.superset_client import SupersetClient
+from superset_tool.models import SupersetConfig
+from pydantic import BaseModel
+# [/SECTION]
+
+router = APIRouter(prefix="/api/environments", tags=["environments"])
+
+# [DEF:EnvironmentResponse:DataClass]
+class EnvironmentResponse(BaseModel):
+    id: str
+    name: str
+    url: str
+# [/DEF:EnvironmentResponse]
+
+# [DEF:DatabaseResponse:DataClass]
+class DatabaseResponse(BaseModel):
+    uuid: str
+    database_name: str
+    engine: Optional[str]
+# [/DEF:DatabaseResponse]
+
+# [DEF:get_environments:Function]
+# @PURPOSE: List all configured environments.
+# @RETURN:  List[EnvironmentResponse]
+@router.get("", response_model=List[EnvironmentResponse])
+async def get_environments(config_manager=Depends(get_config_manager)):
+    envs = config_manager.get_environments()
+    return [EnvironmentResponse(id=e.id, name=e.name, url=e.url) for e in envs]
+# [/DEF:get_environments]
+
+# [DEF:get_environment_databases:Function]
+# @PURPOSE: Fetch the list of databases from a specific environment.
+# @PARAM:   id (str) - The environment ID.
+# @RETURN:  List[Dict] - List of databases.
+@router.get("/{id}/databases")
+async def get_environment_databases(id: str, config_manager=Depends(get_config_manager)):
+    envs = config_manager.get_environments()
+    env = next((e for e in envs if e.id == id), None)
+    if not env:
+        raise HTTPException(status_code=404, detail="Environment not found")
+    
+    try:
+        # Initialize SupersetClient from environment config
+        # Note: We need to map Environment model to SupersetConfig
+        superset_config = SupersetConfig(
+            env=env.name,
+            base_url=env.url,
+            auth={
+                "provider": "db", # Defaulting to db provider
+                "username": env.username,
+                "password": env.password,
+                "refresh": "false"
+            }
+        )
+        client = SupersetClient(superset_config)
+        return client.get_databases_summary()
+    except Exception as e:
+        raise HTTPException(status_code=500, detail=f"Failed to fetch databases: {str(e)}")
+# [/DEF:get_environment_databases]
+
+# [/DEF:backend.src.api.routes.environments]

backend/src/api/routes/mappings.py

@@ -0,0 +1,110 @@
+# [DEF:backend.src.api.routes.mappings:Module]
+#
+# @SEMANTICS: api, mappings, database, fuzzy-matching
+# @PURPOSE:   API endpoints for managing database mappings and getting suggestions.
+# @LAYER:     API
+# @RELATION:  DEPENDS_ON -> backend.src.dependencies
+# @RELATION:  DEPENDS_ON -> backend.src.core.database
+# @RELATION:  DEPENDS_ON -> backend.src.services.mapping_service
+#
+# @INVARIANT: Mappings are persisted in the SQLite database.
+
+# [SECTION: IMPORTS]
+from fastapi import APIRouter, Depends, HTTPException
+from sqlalchemy.orm import Session
+from typing import List, Optional
+from backend.src.dependencies import get_config_manager
+from backend.src.core.database import get_db
+from backend.src.models.mapping import DatabaseMapping
+from pydantic import BaseModel
+# [/SECTION]
+
+router = APIRouter(prefix="/api/mappings", tags=["mappings"])
+
+# [DEF:MappingCreate:DataClass]
+class MappingCreate(BaseModel):
+    source_env_id: str
+    target_env_id: str
+    source_db_uuid: str
+    target_db_uuid: str
+    source_db_name: str
+    target_db_name: str
+# [/DEF:MappingCreate]
+
+# [DEF:MappingResponse:DataClass]
+class MappingResponse(BaseModel):
+    id: str
+    source_env_id: str
+    target_env_id: str
+    source_db_uuid: str
+    target_db_uuid: str
+    source_db_name: str
+    target_db_name: str
+
+    class Config:
+        from_attributes = True
+# [/DEF:MappingResponse]
+
+# [DEF:SuggestRequest:DataClass]
+class SuggestRequest(BaseModel):
+    source_env_id: str
+    target_env_id: str
+# [/DEF:SuggestRequest]
+
+# [DEF:get_mappings:Function]
+# @PURPOSE: List all saved database mappings.
+@router.get("", response_model=List[MappingResponse])
+async def get_mappings(
+    source_env_id: Optional[str] = None,
+    target_env_id: Optional[str] = None,
+    db: Session = Depends(get_db)
+):
+    query = db.query(DatabaseMapping)
+    if source_env_id:
+        query = query.filter(DatabaseMapping.source_env_id == source_env_id)
+    if target_env_id:
+        query = query.filter(DatabaseMapping.target_env_id == target_env_id)
+    return query.all()
+# [/DEF:get_mappings]
+
+# [DEF:create_mapping:Function]
+# @PURPOSE: Create or update a database mapping.
+@router.post("", response_model=MappingResponse)
+async def create_mapping(mapping: MappingCreate, db: Session = Depends(get_db)):
+    # Check if mapping already exists
+    existing = db.query(DatabaseMapping).filter(
+        DatabaseMapping.source_env_id == mapping.source_env_id,
+        DatabaseMapping.target_env_id == mapping.target_env_id,
+        DatabaseMapping.source_db_uuid == mapping.source_db_uuid
+    ).first()
+    
+    if existing:
+        existing.target_db_uuid = mapping.target_db_uuid
+        existing.target_db_name = mapping.target_db_name
+        db.commit()
+        db.refresh(existing)
+        return existing
+    
+    new_mapping = DatabaseMapping(**mapping.dict())
+    db.add(new_mapping)
+    db.commit()
+    db.refresh(new_mapping)
+    return new_mapping
+# [/DEF:create_mapping]
+
+# [DEF:suggest_mappings_api:Function]
+# @PURPOSE: Get suggested mappings based on fuzzy matching.
+@router.post("/suggest")
+async def suggest_mappings_api(
+    request: SuggestRequest,
+    config_manager=Depends(get_config_manager)
+):
+    from backend.src.services.mapping_service import MappingService
+    service = MappingService(config_manager)
+    try:
+        return await service.get_suggestions(request.source_env_id, request.target_env_id)
+    except Exception as e:
+        raise HTTPException(status_code=500, detail=str(e))
+# [/DEF:suggest_mappings_api]
+
+# [/DEF:backend.src.api.routes.mappings]

backend/src/api/routes/tasks.py

@@ -16,6 +16,9 @@ class CreateTaskRequest(BaseModel):
     plugin_id: str
     params: Dict[str, Any]
 
+class ResolveTaskRequest(BaseModel):
+    resolution_params: Dict[str, Any]
+
 @router.post("/", response_model=Task, status_code=status.HTTP_201_CREATED)
 async def create_task(
     request: CreateTaskRequest,
@@ -54,4 +57,19 @@ async def get_task(
     if not task:
         raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Task not found")
     return task
+
+@router.post("/{task_id}/resolve", response_model=Task)
+async def resolve_task(
+    task_id: str,
+    request: ResolveTaskRequest,
+    task_manager: TaskManager = Depends(get_task_manager)
+):
+    """
+    Resolve a task that is awaiting mapping.
+    """
+    try:
+        await task_manager.resolve_task(task_id, request.resolution_params)
+        return task_manager.get_task(task_id)
+    except ValueError as e:
+        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail=str(e))
 # [/DEF]