Adds client-capability-gated tool availability: gateway clients declare
capabilities at connect (new inline-widgets cap), chat.send stamps them into
the run context, and every tool assembly path (embedded runner, queued
followups, Codex app-server harness, plugin-only construction plans) drops
tools whose requiredClientCaps the originating client did not declare. The
Canvas plugin ships the first such tool, show_widget: agents pass SVG or an
HTML fragment plus a title; the plugin hosts it as a bounded, retention-scoped
Canvas document and returns the existing canvas preview handle, which web chat
renders as a sandboxed iframe fitted to the widget's reported content height.
Widget frames never get allow-same-origin (per-preview sandbox ceiling,
including the sidebar path) and the Canvas host serves widget documents with a
CSP sandbox header so direct navigation runs in an opaque origin. Verified
live end-to-end on a Testbox with gpt-5.5 (screenshots on the PR). CLI-backed
model backends do not carry client caps yet and stay fail-closed (#102577).
Closes#101790
Move Canvas, Discord, Slack, voice-call, and WhatsApp skill docs from the root bundled skill tree into their owning plugin packages, with manifest skills declarations and docs/test path updates.
Validation:
- node --import tsx scripts/sync-plugin-versions.ts --check
- node scripts/run-vitest.mjs src/skills/loading/env-path-guidance.test.ts
- autoreview clean
- Crabbox Azure pnpm check:changed run_59ba76511d57 / lease cbx_cbc6750dad72
- wrapper prepare passed pnpm install --frozen-lockfile, pnpm build, and pnpm check before the oversized full local pnpm test was stopped
Follow-up: #95132 remains as the stacked PR for the rest of the starter-skill/Sherpa/ClawHub work.
