…into fix/sdk-ui

# Conflicts:
#	packages/copilot-sdk/src/chat/classes/AbstractChat.ts

# Conflicts:
#	pnpm-lock.yaml

…into fix/sdk-ui

…into fix/sdk-ui

…vior

- 'multi-step' (default) — one bubble per server agent iteration (OpenAI/LiteLLM style), default unchanged
- 'single-turn' — all iterations collapsed into one bubble per user turn (Vercel AI SDK / Claude.ai style)

Usage: <CopilotProvider streamMode="single-turn" />

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Replace the tool-call-based generative UI with a text-streaming approach
(similar to Claude Artifacts pattern). The AI writes HTML wrapped in
<GENUI> tags as part of its text response, which streams naturally and
renders progressively in a sandboxed iframe.

Key changes:

SDK (copilot-sdk/experimental):
- New useGenerativeUI() hook returns wrapMessage for CopilotChat
- New generativeUISystemPrompt() helper for backend system prompts
- New GenUIFrame component: iframe with postMessage, auto-height via
  ResizeObserver, copilot bridge API for interactivity
- Simplified types: removed chart/table/stat/card types, HTML-only
- Deleted CardRenderer, TableRenderer, StatRenderer

SDK (core streaming improvements):
- Progressive action:args emission in Anthropic/OpenAI adapters
- tool-call-start/delta events in providers and stream-text
- Runtime: proper action:args accumulation (don't null currentToolCall)
- AbstractChat: handle action events when streamState is null
- processChunk: parsePartialJson for streaming arg extraction
- connected-chat: attach unmatched streaming executions to messages
- ChatWithTools: allow action:start/args for client tools
- AbstractAgentLoop: reuse streaming executions

Example (generative-ui-demo):
- Rewritten with sidebar, dicebear avatars, copilot logo
- Uses generativeUISystemPrompt() + loadSkills() on backend
- Skills system with frontend-design skill (eager)
- SaaS dashboard copilot context (Acme Inc.)

Docs:
- Rewritten generative-ui.mdx with two approaches documented
- Updated BETA-FEATURES.md

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

…x/sdk-ui

- AbstractChat: check toolResults.size in message:end so tool-only turns
  reset streamState and don't attach next turn's tools to previous message
- AbstractChat: in single-turn mode parent insertChainParentId from message
  before the streaming message, not from streamState.messageId
- AbstractChat: skip role:tool messages from done.messages in single-turn
  (already in streamState.toolResults, re-inserting creates duplicates)
- connected-chat: restrict liveExecutions to last assistant message only;
  prefer metadata.toolExecutions for historical messages
- connected-chat: filter unmatched executions to pending/executing only
  so stale completed cards don't bleed into new streaming message
- connected-chat: null-safe message filter to prevent render crashes

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Previously request.systemPrompt || this.config.systemPrompt meant a
client-sent prompt could silently override the server-configured one,
breaking generativeUISystemPrompt and any server-side prompt setup.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>