ecosystem-extensions-v2 Tasks

1. Spec and RED tests

• 1.1 Add proposal, design, tasks, and spec delta for optional ecosystem integrations
• 1.2 Add failing tests for capability reporting and explicit-unavailable backend behavior

2. Capability layer

• 2.1 Add an ecosystem capability registry for CV-CUDA, TensorRT, and GStreamer
• 2.2 Add build flags / compile definitions so optional backends stay dependency-gated

3. Optional integrations

• 3.1 Add a CV-CUDA-backed operator surface with explicit unavailable behavior by default
• 3.2 Add a TensorRT inference operator surface with explicit unavailable behavior by default
• 3.3 Add a GStreamer / DeepStream bridge surface with explicit unavailable behavior by default

4. Docs and verification

• 4.1 Update README / README.zh-CN for optional ecosystem integrations
• 4.2 Run strict OpenSpec validation plus build/test verification