feat(studio): support plugin trace views

[ryana]

Summary

• add an optional traceViews export to the runtime-loaded Studio web-plugin contract established by feat(studio): plugin system — web UI, nav, and /apis/plugins discovery NVIDIA-NeMo/nemo-platform#594
• render plugin trace modes and background activity inside Studio's existing React, router, KUI, and TanStack Query providers
• expose the generic AssistantChat primitive through @nemo/common, including trusted Markdown link rendering for plugin-owned citations
• move all Zoomer-specific backend, polling, hierarchy UI, contextual Q&A, and citation behavior into the standalone public ryana/nemo-zoomer-plugin repository
• keep this platform change feature-agnostic: Studio owns discovery, mode selection, host injection, and crash containment only

Validation

Platform:

• full pre-commit suite passed
• Studio and Common TypeScript typechecks passed
• Common test suite: 115 files / 1,453 tests passed
• trace-view contract and renderer tests: 4 files / 14 tests passed

Standalone Zoomer plugin:

• Python suite against stable and post-feat(studio): plugin system — web UI, nav, and /apis/plugins discovery NVIDIA-NeMo/nemo-platform#594 plugin APIs: 15 tests passed in each environment
• Ruff format and lint passed
• frontend typecheck passed
• frontend unit suite: 2 files / 5 tests passed
• production bundle build passed and the built bundle is included in the wheel
• standalone repository CI: Python and web jobs passed

Compatibility

The current stable nemo-platform-plugin release predates StudioSpec. Zoomer's backend remains installable there and the Studio entry point fails with an explicit compatibility message. The full Studio UI requires NeMo Platform main/NVIDIA-NeMo#594-or-newer until the next stable plugin API release.

Tracking

• AIRE-834
• AIRE-836