Update package READMEs + ARCHITECTURE for the assistant pane, native streaming,
and the new onThreadStarted / setSuggestedPrompts / setTitle surface. Reverse
the slack.mdx callout that told users to delete the assistant scopes (now
required), and enable the pane in the examples/slack manifest (assistant_view +
assistant:write + assistant_thread_* events) with a dev-ex onThreadStarted
greeting and the assistant config.
100% JSX bot at feature parity with the PoC example: issue/page cards,
tables, Chart.js charts, Mermaid diagrams, incident/status/links cards,
a confirm_write HITL gate, and /agent + /triage slash commands.
Registers examples/slack in the pnpm workspace.
Alem Tuzlak