fix: persist edge animation mode (None/Snake/Flow) end-to-end

- canvasStore.onConnect: include animated in edge data object (was silently dropped)
- Backend schemas: normalize animated bool/int to string ('none'/'snake'/'flow') via field_validator
- ORM model: change animated column from Boolean to String
- DB migration: convert existing 0/1 boolean rows to 'none'/'snake' strings

backend/app/db/database.py

@@ -2,6 +2,7 @@ from collections.abc import AsyncGenerator
 from contextlib import suppress
 from pathlib import Path
 
+from sqlalchemy.exc import OperationalError
 from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_async_engine
 from sqlalchemy.orm import DeclarativeBase
 
@@ -26,36 +27,42 @@ async def init_db() -> None:
     async with engine.begin() as conn:
         await conn.run_sync(Base.metadata.create_all)
         # Add columns introduced after initial schema (idempotent)
-        with suppress(Exception):
+        with suppress(OperationalError):
             await conn.exec_driver_sql("ALTER TABLE nodes ADD COLUMN container_mode BOOLEAN NOT NULL DEFAULT 0")
-        with suppress(Exception):
+        with suppress(OperationalError):
             await conn.exec_driver_sql("ALTER TABLE nodes ADD COLUMN custom_colors JSON")
-        with suppress(Exception):
+        with suppress(OperationalError):
             await conn.exec_driver_sql("ALTER TABLE edges ADD COLUMN custom_color TEXT")
-        with suppress(Exception):
+        with suppress(OperationalError):
             await conn.exec_driver_sql("ALTER TABLE edges ADD COLUMN path_style TEXT")
-        with suppress(Exception):
+        with suppress(OperationalError):
             await conn.exec_driver_sql("ALTER TABLE nodes ADD COLUMN custom_icon TEXT")
-        with suppress(Exception):
+        with suppress(OperationalError):
             await conn.exec_driver_sql("ALTER TABLE edges ADD COLUMN source_handle TEXT")
-        with suppress(Exception):
+        with suppress(OperationalError):
             await conn.exec_driver_sql("ALTER TABLE edges ADD COLUMN target_handle TEXT")
-        with suppress(Exception):
+        with suppress(OperationalError):
             await conn.exec_driver_sql("ALTER TABLE edges ADD COLUMN animated BOOLEAN NOT NULL DEFAULT 0")
-        with suppress(Exception):
+        with suppress(OperationalError):
             await conn.exec_driver_sql("ALTER TABLE nodes ADD COLUMN cpu_count INTEGER")
-        with suppress(Exception):
+        with suppress(OperationalError):
             await conn.exec_driver_sql("ALTER TABLE nodes ADD COLUMN cpu_model TEXT")
-        with suppress(Exception):
+        with suppress(OperationalError):
             await conn.exec_driver_sql("ALTER TABLE nodes ADD COLUMN ram_gb REAL")
-        with suppress(Exception):
+        with suppress(OperationalError):
             await conn.exec_driver_sql("ALTER TABLE nodes ADD COLUMN disk_gb REAL")
-        with suppress(Exception):
+        with suppress(OperationalError):
             await conn.exec_driver_sql("ALTER TABLE nodes ADD COLUMN show_hardware BOOLEAN NOT NULL DEFAULT 0")
-        with suppress(Exception):
+        with suppress(OperationalError):
             await conn.exec_driver_sql("ALTER TABLE nodes ADD COLUMN width REAL")
-        with suppress(Exception):
+        with suppress(OperationalError):
             await conn.exec_driver_sql("ALTER TABLE nodes ADD COLUMN height REAL")
+        # Migrate animated column from boolean (0/1) to string ('none'/'snake')
+        with suppress(OperationalError):
+            await conn.exec_driver_sql("UPDATE edges SET animated = 'snake' WHERE animated = '1' OR animated = 1")
+        with suppress(OperationalError):
+            sql = "UPDATE edges SET animated = 'none' WHERE animated = '0' OR animated = 0 OR animated IS NULL"
+            await conn.exec_driver_sql(sql)
 
 
 async def get_db() -> AsyncGenerator[AsyncSession, None]:

backend/app/db/models.py

@@ -33,7 +33,7 @@ class Node(Base):
     notes: Mapped[str | None] = mapped_column(Text)
     pos_x: Mapped[float] = mapped_column(Float, default=0)
     pos_y: Mapped[float] = mapped_column(Float, default=0)
-    parent_id: Mapped[str | None] = mapped_column(String, ForeignKey("nodes.id"))
+    parent_id: Mapped[str | None] = mapped_column(String, ForeignKey("nodes.id", ondelete="CASCADE"))
     container_mode: Mapped[bool] = mapped_column(Boolean, default=False)
     custom_colors: Mapped[dict[str, Any] | None] = mapped_column(JSON, nullable=True)
     custom_icon: Mapped[str | None] = mapped_column(String, nullable=True)
@@ -65,7 +65,7 @@ class Edge(Base):
     speed: Mapped[str | None] = mapped_column(String)
     custom_color: Mapped[str | None] = mapped_column(String)
     path_style: Mapped[str | None] = mapped_column(String)
-    animated: Mapped[bool] = mapped_column(Boolean, default=False)
+    animated: Mapped[str] = mapped_column(String, nullable=False, default='none')
     source_handle: Mapped[str | None] = mapped_column(String)
     target_handle: Mapped[str | None] = mapped_column(String)
     created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=_now)