Merge tasks into notes: a task is just a note with task attributes

A task is now a note with status/priority/due_date columns set (status IS NOT NULL).
This eliminates the separate tasks table, companion note system, cascade deletes,
bidirectional title sync, and _skip_cascade flags.

Migration (0004):
- Add status, priority, due_date columns to notes table
- Migrate task data from companion notes and orphan tasks
- Drop tasks table and old enum types

Backend:
- models/note.py: Add TaskStatus/TaskPriority enums, task columns, is_task property
- models/task.py: Deleted (merged into note.py)
- models/__init__.py: Re-export enums from note.py, remove Task import
- services/notes.py: Remove companion/cascade logic, add is_task filter,
  convert_note_to_task, convert_task_to_note, simplified backlinks
- services/tasks.py: Rewritten as thin wrappers around notes service
- routes/notes.py: Add is_task filter (default false), task fields in CRUD,
  convert-to-note endpoint
- routes/tasks.py: description→body (with fallback), remove note_id filter

Frontend:
- types/note.ts: Add TaskStatus, TaskPriority, task fields to Note interface
- types/task.ts: Task is now a re-export alias for Note
- stores/notes.ts: Simplify convertToTask, add convertToNote
- stores/tasks.ts: description→body in createTask/updateTask
- TaskEditorView: description→body, remove companion note UI
- TaskViewerView: description→body, remove companion note link, add Convert to Note
- NoteViewerView: Remove companion task UI, simplify convert-to-task
- TaskCard: description→body, non-null assertions for status/priority

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/fabledassistant/routes/notes.py

@@ -1,7 +1,10 @@
+from datetime import date
+
 from quart import Blueprint, jsonify, request
 
 from fabledassistant.services.notes import (
     convert_note_to_task,
+    convert_task_to_note,
     create_note,
     delete_note,
     get_all_tags,
@@ -26,8 +29,15 @@ async def list_notes_route():
     limit = request.args.get("limit", 50, type=int)
     offset = request.args.get("offset", 0, type=int)
 
+    # Default to non-task notes only; ?is_task=true for tasks, ?all=true for everything
+    is_task: bool | None = False
+    if request.args.get("all", "").lower() == "true":
+        is_task = None
+    elif request.args.get("is_task", "").lower() == "true":
+        is_task = True
+
     notes, total = await list_notes(
-        q=q, tags=tag or None, sort=sort, order=order, limit=limit, offset=offset
+        q=q, tags=tag or None, is_task=is_task, sort=sort, order=order, limit=limit, offset=offset
     )
     return jsonify({"notes": [n.to_dict() for n in notes], "total": total})
 
@@ -37,11 +47,22 @@ async def create_note_route():
     data = await request.get_json()
     body = data.get("body", "")
     tags = extract_tags(body)
+
+    # Optional task fields
+    status = data.get("status")
+    priority = data.get("priority")
+    due_date = None
+    if data.get("due_date"):
+        due_date = date.fromisoformat(data["due_date"])
+
     note = await create_note(
         title=data.get("title", ""),
         body=body,
         tags=tags,
         parent_id=data.get("parent_id"),
+        status=status,
+        priority=priority,
+        due_date=due_date,
     )
     return jsonify(note.to_dict()), 201
 
@@ -86,9 +107,15 @@ async def get_note_route(note_id: int):
 async def update_note_route(note_id: int):
     data = await request.get_json()
     fields = {}
-    for key in ("title", "body", "parent_id"):
+    for key in ("title", "body", "parent_id", "status", "priority"):
         if key in data:
             fields[key] = data[key]
+
+    if "due_date" in data:
+        fields["due_date"] = (
+            date.fromisoformat(data["due_date"]) if data["due_date"] else None
+        )
+
     if "body" in fields:
         fields["tags"] = extract_tags(fields["body"])
     note = await update_note(note_id, **fields)
@@ -108,8 +135,17 @@ async def delete_note_route(note_id: int):
 @notes_bp.route("/<int:note_id>/convert-to-task", methods=["POST"])
 async def convert_note_to_task_route(note_id: int):
     try:
-        task = await convert_note_to_task(note_id)
-        return jsonify(task.to_dict()), 201
+        note = await convert_note_to_task(note_id)
+        return jsonify(note.to_dict()), 200
+    except ValueError as e:
+        return jsonify({"error": str(e)}), 404
+
+
+@notes_bp.route("/<int:note_id>/convert-to-note", methods=["POST"])
+async def convert_task_to_note_route(note_id: int):
+    try:
+        note = await convert_task_to_note(note_id)
+        return jsonify(note.to_dict()), 200
     except ValueError as e:
         return jsonify({"error": str(e)}), 404