fix(mcp): keep Claude imports pending until connect

[onlyfeng]

Summary

Keep MCP servers imported from Claude config in pending status during MCP service initialization. They should not eagerly connect until the user explicitly calls connect().

Root Cause

The MCP initialization path iterates every configured MCP server and immediately calls create(). Claude-origin servers are imported into config with origin metadata, but that metadata was not used to preserve the expected lazy connection behavior.

Changes

• Detect cfg.mcp_origins?.[key]?.type === "claude" during MCP state initialization.
• Set those servers to { status: "pending" } and skip eager create().
• Existing explicit connect() behavior remains unchanged.

Validation

• bun typecheck
• bun test --timeout 60000 test/mcp/lifecycle.test.ts

CI Status Note

• lint and typecheck pass on this PR.
• Full unit currently fails, but upstream/main@ee4ddd2 already has a failing test workflow (run 28071223407).
• This PR fixes its target failure: Claude Code local MCP server is pending until explicitly connected is absent from this PR unit failure list.
• The remaining failed subtask preserves metadata on error tool state failure is covered by companion PR fix(session): preserve failed subtask metadata #1268, not this MCP change.
• The CheckpointContext producer, parentSessionID end-to-end, and session.llm.stream failures are also present on current upstream/main and are outside this diff.