Docs: align Claude Code runtime references to @anthropic-ai/claude-code@2.1.42

[SomeoneKong]

Summary

This PR updates the Claude Agent SDK documentation set to accurately reflect the Claude Code v2.1.42 runtime surface and to make code references reproducible for readers.

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What Changed

Portable source references (bundle + search anchors)

• Standardized Claude Code implementation references to @anthropic-ai/claude-code/cli.js using search anchors (strings/symbols) instead of local unpacked paths or line numbers.

Runtime surface updates (v2.1.42)

• Updated tool/hook/permission mode coverage to match v2.1.42 runtime behavior.
• Added dedicated topic docs for:
  • docs/claude-agent-sdk/lsp.md (LSP integration + LSP tool)
  • docs/claude-agent-sdk/toolsearch.md (deferred tool discovery/selection + ToolSearch tool)
• Updated docs/claude-agent-sdk/tools-complete.md to include ToolSearch and LSP and to reflect a 30-tool runtime surface.

Navigation fixes

• Added a minimal hub at docs/claude-code/README.md because docs/claude-agent-sdk/README.md already referenced it.

Targeted cleanup

• Removed a few stale/brittle references (for example “Line N in cli.js” or older version footers) in favor of current-state descriptions.
• Updated a handful of hard-coded counts that were drifting.