GeezerVison

Why

Node.js exposes TracingChannel in node:diagnostics_channel, but devframe has no way to see what an app traces, and devframe does not publish traces of its own work. This plan gives executors a settled design for both.

What

Adds plans/009-tracing-channels.md and its row in plans/README.md. The plan fixes the decisions made with the maintainer:

• ctx.tracing in devframe core: register, list, record, stop, records, clear, onRecord. Core owns the wire pieces (shared state devframe:tracing:channels, stream devframe:tracing, RPC devframe:tracing:record|stop|clear).
• On-demand subscription so the user app pays no tracing cost until someone presses Record. Five phases grouped into one record per context. Ring buffer of 500 per channel.
• A Tracing tab in the inspect plugin, split pane like the State tab.
• Phase 2: devframe traces its own RPC calls and shared-state writes through the same primitive, with the tracing wire pieces excluded.
• Node and Bun supported. No-op plus one DF0081 on Deno.

Three PRs, each passing the full gate on its own.

Created with the help of an agent.