优化 Runtime 安装进度体验

- 状态栏与窗口强制刷新，进度更新无需移动鼠标即可实时显示
- 安装过程拆分为 12 个阶段，每段进度从 0 到 100%
- 安装阶段解析 uv 下载事件推进进度，模型下载阶段实时反映字节进度

src/snapform/worker.py

@@ -32,10 +32,23 @@ def check_cancelled(cancel_check):
         raise TaskCancelled("Task cancelled")
 
 
-def write_status(path, progress, message, error=None, state=None):
+def write_status(
+    path,
+    progress,
+    message,
+    error=None,
+    state=None,
+    stage=None,
+    stages=None,
+    stage_label=None,
+):
     payload = {"progress": progress, "message": message}
     if error:
         payload["error"] = error
+    if stage is not None:
+        payload["stage"] = stage
+        payload["stages"] = stages
+        payload["stage_label"] = stage_label
     if state is None:
         if error:
             state = "failed"
@@ -136,12 +149,27 @@ def prepare_input(input_path, video_frames, temporary_root, cancel_check=None):
 
 
 class DownloadProgressReporter:
-    def __init__(self, status_path, repository, clock=time.monotonic):
+    def __init__(
+        self,
+        status_path,
+        repository,
+        clock=time.monotonic,
+        start=0.05,
+        span=0.90,
+        stage=None,
+        stages=None,
+        stage_label=None,
+    ):
         self.status_path = status_path
         self.repository = repository
         self.clock = clock
         self.lock = threading.Lock()
-        self.progress = 0.05
+        self.start = start
+        self.span = span
+        self.stage = stage
+        self.stages = stages
+        self.stage_label = stage_label
+        self.progress = start
         self.last_write_time = 0.0
 
     def report(self, current, total):
@@ -149,7 +177,7 @@ class DownloadProgressReporter:
             return
 
         factor = min(max(current / total, 0.0), 1.0)
-        progress = 0.05 + factor * 0.90
+        progress = self.start + factor * self.span
         now = self.clock()
         with self.lock:
             if progress <= self.progress:
@@ -162,6 +190,9 @@ class DownloadProgressReporter:
                 self.status_path,
                 progress,
                 f"Downloading {self.repository}",
+                stage=self.stage,
+                stages=self.stages,
+                stage_label=self.stage_label,
             )
 
 
@@ -170,11 +201,25 @@ def create_download_progress_class(
     repository,
     tqdm_type=None,
     clock=time.monotonic,
+    start=0.05,
+    span=0.90,
+    stage=None,
+    stages=None,
+    stage_label=None,
 ):
     if tqdm_type is None:
         from tqdm.auto import tqdm as tqdm_type
 
-    reporter = DownloadProgressReporter(status_path, repository, clock)
+    reporter = DownloadProgressReporter(
+        status_path,
+        repository,
+        clock,
+        start,
+        span,
+        stage,
+        stages,
+        stage_label,
+    )
 
     class DownloadProgress(tqdm_type):
         def __init__(self, *args, **kwargs):
@@ -205,10 +250,26 @@ def download_model(args):
 
     model_dir = Path(args.model_dir)
     model_dir.mkdir(parents=True, exist_ok=True)
-    write_status(args.status, 0.05, f"Downloading {args.repository}")
+    staged = getattr(args, "stage", None) is not None
+    start = 0.0 if staged else 0.05
+    span = 1.0 if staged else 0.90
+    stage_kwargs = {
+        "stage": getattr(args, "stage", None),
+        "stages": getattr(args, "stages", None),
+        "stage_label": getattr(args, "stage_label", None),
+    }
+    write_status(
+        args.status,
+        start,
+        f"Downloading {args.repository}",
+        **stage_kwargs,
+    )
     progress_class = create_download_progress_class(
         args.status,
         args.repository,
+        start=start,
+        span=span,
+        **stage_kwargs,
     )
     snapshot_download(
         repo_id=args.repository,
@@ -216,7 +277,12 @@ def download_model(args):
         tqdm_class=progress_class,
         allow_patterns=args.allow_pattern or None,
     )
-    write_status(args.status, 1.0, "Model is ready")
+    write_status(
+        args.status,
+        1.0,
+        "Model is ready",
+        **stage_kwargs,
+    )
 
 
 def select_device(requested, torch):
@@ -480,6 +546,9 @@ def parser():
     download.add_argument("--model-dir", required=True)
     download.add_argument("--status", required=True)
     download.add_argument("--allow-pattern", action="append", default=[])
+    download.add_argument("--stage", type=int, default=None)
+    download.add_argument("--stages", type=int, default=None)
+    download.add_argument("--stage-label", default=None)
 
     background = commands.add_parser("remove-background")
     background.add_argument("--input", required=True)