{BugFix} Allow Aria Data Plotter to connect to existing rerun instance

Summary:
This diff implements the fix for streaming in Electron frozen Linux build.

**Problem:**
In the frozen Electron build, streaming data does not flow because the Rerun viewer is not started via the frozen-safe pattern. The streaming worker process calls `rr.spawn()` which cannot launch the bundled binary correctly in frozen mode.

**Solution:**
Modify both Aria Studio and the ClientSDK to use the frozen-safe pattern for streaming:

1. **Aria Studio (`device_manager_new.py`)**:
   - Added `await rerun_manager.start_frozen_rerun()` before `start_viewer()` in `start_streaming()`,
   - Added `await rerun_manager.start_frozen_rerun()` before `start_viewer()` in `reopen_streaming_viewer()`,
   - This matches the VRS playback pattern and ensures the viewer is available for gRPC connection.

2. **Aria Studio (`streaming_rerun_task.py`)**:
   - Added frozen mode detection (`is_frozen = getattr(sys, 'frozen', False) and hasattr(sys, '_MEIPASS')`),
   - Pass `connect_to_existing_viewer=is_frozen` to `AriaStreamManager`.

3. **ClientSDK (`aria_streaming_viewer.py`)**:
   - Added `connect_to_existing_viewer: bool = False` parameter to `AriaStreamManager.__init__()`,
   - Added `connect_to_existing_viewer: bool = False` parameter to `AriaStreamingViewer.__init__()`,
   - Pass the flag through to `AriaDataViewerConfig`.

4. **Project Aria Tools (`aria_data_plotter.py`)**:
   - Added `connect_to_existing: bool = False` field to `AriaDataViewerConfig`,
   - Modified `AriaDataViewer.__init__()` to call `rr.connect_grpc()` instead of `rr.spawn()` when `config.connect_to_existing` is `True`,
   - The change is backward compatible (default `False` preserves existing behavior)

DevMate plan:  {F1991375964}

Reviewed By: SeaOtocinclus

Differential Revision: D108909540

fbshipit-source-id: ccf3a653f0044f5e4855f90cdfc1abc4fc5dcba8

Author: Piotr Brzyski

projectaria_tools/tools/aria_rerun_viewer/aria_data_plotter.py

@@ -166,6 +166,11 @@ class AriaDataViewerConfig:
     # Whether to show latency plot in the blueprint (only relevant for streaming)
     show_latency: bool = False
 
+    # Whether to connect to an existing Rerun viewer via gRPC instead of spawning
+    # a new viewer process. Used for frozen Electron builds where the viewer is
+    # already started by the parent process via start_frozen_rerun().
+    connect_to_existing_viewer: bool = False
+
 
 class AriaDataViewer:
     """
@@ -258,6 +263,12 @@ def __init__(
         if rrd_output_path:
             rr.init("AriaDataViewer", spawn=False)
             rr.save(rrd_output_path)
+        elif self.config.connect_to_existing_viewer:
+            rr.init("AriaDataViewer")
+            rr.connect_grpc()
+            # If a blueprint path is configured, load it after connecting
+            if self.config.blueprint_path:
+                rr.log_file_from_path(self.config.blueprint_path)
         elif self.config.blueprint_path:
             self._spawn_rerun_with_blueprint(
                 self.config.blueprint_path, self.config.rerun_memory_limit