Fix the MQTT node, suggest message names, and drop Items

- MQTT nodes failed to build: the topic map was renamed to talk in ports, but
  __slots__ still declared the old name, so every MQTT node raised
  AttributeError. Building one of each node type is now a test, since __slots__
  makes this failure invisible until someone places the node.
- Port names offer the messages already in play: everything published is worth
  reading, and an input nobody provides yet is worth publishing. A message only
  connects when both ends spell it the same way, so choosing beats typing.
- Adding a port focuses its name field.
- Dragging onto an input that already reads something offers the extra port as
  well as the replacement — an MQTT or InfluxDB node usually wants both.
- The template's Item model, its routes, screens and table are gone.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016WzrvW7rjQbynnhF6pxh6i

backend/app/api/main.py

@@ -1,13 +1,12 @@
 from fastapi import APIRouter
 
-from app.api.routes import flows, items, login, private, secrets, users, utils
+from app.api.routes import flows, login, private, secrets, users, utils
 from app.core.config import settings
 
 api_router = APIRouter()
 api_router.include_router(login.router)
 api_router.include_router(users.router)
 api_router.include_router(utils.router)
-api_router.include_router(items.router)
 api_router.include_router(flows.router)
 api_router.include_router(flows.ws_router)
 api_router.include_router(secrets.router)

backend/app/api/routes/items.py

@@ -1,112 +0,0 @@
-import uuid
-from typing import Any
-
-from fastapi import APIRouter, HTTPException
-from sqlmodel import col, func, select
-
-from app.api.deps import CurrentUser, SessionDep
-from app.models import Item, ItemCreate, ItemPublic, ItemsPublic, ItemUpdate, Message
-
-router = APIRouter(prefix="/items", tags=["items"])
-
-
-@router.get("/", response_model=ItemsPublic)
-def read_items(
-    session: SessionDep, current_user: CurrentUser, skip: int = 0, limit: int = 100
-) -> Any:
-    """
-    Retrieve items.
-    """
-
-    if current_user.is_superuser:
-        count_statement = select(func.count()).select_from(Item)
-        count = session.exec(count_statement).one()
-        statement = (
-            select(Item).order_by(col(Item.created_at).desc()).offset(skip).limit(limit)
-        )
-        items = session.exec(statement).all()
-    else:
-        count_statement = (
-            select(func.count())
-            .select_from(Item)
-            .where(Item.owner_id == current_user.id)
-        )
-        count = session.exec(count_statement).one()
-        statement = (
-            select(Item)
-            .where(Item.owner_id == current_user.id)
-            .order_by(col(Item.created_at).desc())
-            .offset(skip)
-            .limit(limit)
-        )
-        items = session.exec(statement).all()
-
-    return ItemsPublic(data=items, count=count)
-
-
-@router.get("/{id}", response_model=ItemPublic)
-def read_item(session: SessionDep, current_user: CurrentUser, id: uuid.UUID) -> Any:
-    """
-    Get item by ID.
-    """
-    item = session.get(Item, id)
-    if not item:
-        raise HTTPException(status_code=404, detail="Item not found")
-    if not current_user.is_superuser and (item.owner_id != current_user.id):
-        raise HTTPException(status_code=403, detail="Not enough permissions")
-    return item
-
-
-@router.post("/", response_model=ItemPublic)
-def create_item(
-    *, session: SessionDep, current_user: CurrentUser, item_in: ItemCreate
-) -> Any:
-    """
-    Create new item.
-    """
-    item = Item.model_validate(item_in, update={"owner_id": current_user.id})
-    session.add(item)
-    session.commit()
-    session.refresh(item)
-    return item
-
-
-@router.put("/{id}", response_model=ItemPublic)
-def update_item(
-    *,
-    session: SessionDep,
-    current_user: CurrentUser,
-    id: uuid.UUID,
-    item_in: ItemUpdate,
-) -> Any:
-    """
-    Update an item.
-    """
-    item = session.get(Item, id)
-    if not item:
-        raise HTTPException(status_code=404, detail="Item not found")
-    if not current_user.is_superuser and (item.owner_id != current_user.id):
-        raise HTTPException(status_code=403, detail="Not enough permissions")
-    update_dict = item_in.model_dump(exclude_unset=True)
-    item.sqlmodel_update(update_dict)
-    session.add(item)
-    session.commit()
-    session.refresh(item)
-    return item
-
-
-@router.delete("/{id}")
-def delete_item(
-    session: SessionDep, current_user: CurrentUser, id: uuid.UUID
-) -> Message:
-    """
-    Delete an item.
-    """
-    item = session.get(Item, id)
-    if not item:
-        raise HTTPException(status_code=404, detail="Item not found")
-    if not current_user.is_superuser and (item.owner_id != current_user.id):
-        raise HTTPException(status_code=403, detail="Not enough permissions")
-    session.delete(item)
-    session.commit()
-    return Message(message="Item deleted successfully")

backend/app/api/routes/users.py

@@ -2,7 +2,7 @@ import uuid
 from typing import Any
 
 from fastapi import APIRouter, Depends, HTTPException
-from sqlmodel import col, delete, func, select
+from sqlmodel import col, func, select
 
 from app import crud
 from app.api.deps import (
@@ -13,7 +13,6 @@ from app.api.deps import (
 from app.core.config import settings
 from app.core.security import get_password_hash, verify_password
 from app.models import (
-    Item,
     Message,
     UpdatePassword,
     User,
@@ -224,8 +223,6 @@ def delete_user(
         raise HTTPException(
             status_code=403, detail="Super users are not allowed to delete themselves"
         )
-    statement = delete(Item).where(col(Item.owner_id) == user_id)
-    session.exec(statement)
     session.delete(user)
     session.commit()
     return Message(message="User deleted successfully")