feat(sciqlop_claude): add Claude chat backend plugin

[jeandet]

Summary

Adds sciqlop_claude, a thin adapter between SciQLop's new agent chat framework and claude-agent-sdk.

• Registers a ClaudeBackend with SciQLop's agent registry; the shared AgentChatDock handles all the UI.
• Wraps the SciQLop tool surface (build_sciqlop_tools) into an in-process MCP server exposed to Claude via the SDK's create_sdk_mcp_server.
• Streams assistant text and tool-result images as typed content blocks the dock renders inline.
• Resumes prior Claude Code sessions from ~/.claude/projects/<cwd-mangled>/*.jsonl, reconstructing the transcript (text blocks + screenshots) without replaying hidden thinking / tool-use chrome.
• Gates write tools behind the dock's per-call approval dialog via can_use_tool.

Authentication comes from the user's existing Claude Code OAuth login (the SDK spawns the claude CLI over stdio), so no API key is required.

Dependency

This plugin depends on SciQLop PR SciQLop/SciQLop#107 (the agent framework under SciQLop/components/agents/). Until that merges, the plugin will only work against a SciQLop checkout including that branch.

Test plan

• uv pip install -e sciqlop_claude/
• Launch SciQLop with claude CLI available on PATH
• Open the Agents dock, pick "Claude" from the backend dropdown
• Send a text prompt; confirm streaming markdown response
• Ask Claude to sciqlop_screenshot_panel and verify the PNG renders inline
• Toggle "Allow write actions" and ask Claude to create a panel + plot a product
• Pick a prior session from the "Resume session…" dropdown and verify the transcript replays

🤖 Generated with Claude Code