feat(FN-007): implement repository connection API and git operations

- Add GitHubAdapter and GitLabAdapter with URL parsing
- Create provider factory in apps/api/app/git/providers/
- Implement clone, fetch, push in LocalGitOperations
- Add repository_connections router with CRUD and SSH key endpoints
- Create RepositoryConnection schema with validation
- Update models and routers __init__.py for new components
- Add comprehensive tests for git operations

apps/api/app/schemas/repository_connection.py

@@ -0,0 +1,35 @@
+from uuid import UUID
+
+from app.schemas.base import OrmBase
+
+
+class RepositoryConnectionBase(OrmBase):
+    project_id: UUID
+    repository_id: UUID | None = None
+    provider_kind: str = "generic"
+    credential_id: UUID | None = None
+    connection_status: str = "pending"
+    default_branch: str | None = None
+
+
+class RepositoryConnectionCreate(OrmBase):
+    repository_id: UUID
+    provider_kind: str
+    credential_kind: str
+    credential_payload: str
+
+
+class RepositoryConnectionRead(OrmBase):
+    id: UUID
+    project_id: UUID
+    repository_id: UUID | None = None
+    provider_kind: str
+    credential_id: UUID | None = None
+    connection_status: str
+    default_branch: str | None = None
+
+
+class SshKeyResponse(OrmBase):
+    connection_id: UUID
+    public_key: str
+    credential_id: UUID