feat: per-task image/annotations, annotation editor toolbar, Tailwind compiled

- Add per-task file upload with image preview in task editor
- Add dedicated annotation editor page (task_drawing.html) with Fabric.js
- Add color picker, stroke width, and line dash controls to annotation toolbar
- Apply property changes to selected objects in real-time
- Disable style controls until a drawing tool or object is selected
- Remove zoom/pan from annotation toolbar (simplified UX)
- Auto-switch to select mode after placing annotation elements
- Show annotation overlay on task image previews (read-only canvas)
- Add file proxy route in measure blueprint for task file access
- Add file_path/file_type fields to TaskCreate/TaskUpdate Pydantic schemas
- Replace Tailwind CDN with compiled CSS (tailwind.config.js with full shades)
- Fix Alpine.js x-init crash: extract annotations JSON to <script> tags
  (recipe_preview.html, task_execute.html) to avoid HTML attribute breakage

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

server/schemas/task.py

@@ -51,6 +51,7 @@ class TaskCreate(BaseModel):
     title: str = Field(..., min_length=1, max_length=255)
     directive: Optional[str] = None
     description: Optional[str] = None
+    file_path: Optional[str] = Field(None, max_length=500)
     file_type: Optional[str] = Field(None, pattern="^(image|pdf)$")
     annotations_json: Optional[dict[str, Any]] = None
     subtasks: list[SubtaskCreate] = []
@@ -61,6 +62,8 @@ class TaskUpdate(BaseModel):
     title: Optional[str] = Field(None, min_length=1, max_length=255)
     directive: Optional[str] = None
     description: Optional[str] = None
+    file_path: Optional[str] = Field(None, max_length=500)
+    file_type: Optional[str] = Field(None, pattern="^(image|pdf)$")
     annotations_json: Optional[dict[str, Any]] = None