[codex] Fix Claude installer and MCP context issues

[Ununp3ntium115]

Summary

This PR fixes the Claude-facing issue reports by tightening the installer, permissions, MCP tool guidance, and ArkTS file detection:

• Add mcp__codegraph__codegraph_files to Claude auto-allow permissions so the newly exposed file-list tool is actually usable after install.
• Create best-effort .backup / .backup.N files before installer overwrites existing agent config, including corrupted JSON recovery paths.
• Reword codegraph_context schema and server instructions so agents pass short symbols, routes, filenames, API names, or keyword fragments instead of verbose prose tasks.
• Map ArkTS .ets files to the TypeScript grammar for first-pass indexing, with source-file detection coverage.

Issue Mapping

• Fixes Bug: Claude installer auto-allow omits codegraph_files despite the README/manual Claude example including it #565: Claude auto-allow now includes codegraph_files.
• Fixes change config or setting with out backup #486: installer writes now preserve restore points instead of overwriting configs without a backup.
• Fixes codegraph_context task parameter description misleads models into passing natural language instead of keywords #571: codegraph_context is documented as keyword-backed and no longer framed as the first tool for arbitrary natural-language tasks.
• Fixes About HarmonyOS and ArkTS #512: .ets files are recognized as TypeScript-compatible source files.

Root Cause

The Claude installer permission list had drifted from the MCP tool surface, so installed Claude configs could omit a tool that CodeGraph now exposes. The shared installer writer also wrote atomically but did not preserve prior content before replacing config files, which made recovery poor when the installer had to rewrite existing config.

Separately, codegraph_context combines search and graph expansion, but its schema and instructions described it as accepting broad task descriptions. That encouraged agents to send natural-language prompts into a keyword-backed lookup, reducing result quality. ArkTS files were also skipped because extension detection had no .ets mapping even though the TypeScript grammar is an acceptable first-pass parser for common ArkTS syntax.

Validation

• npx -y -p node@22 node ./node_modules/vitest/vitest.mjs run __tests__/installer.test.ts __tests__/installer-targets.test.ts __tests__/security.test.ts __tests__/extraction.test.ts __tests__/mcp-tool-allowlist.test.ts
  • 5 files passed, 459 passed, 2 skipped
• npm run build
• git diff --check

Notes

This PR intentionally keeps the Claude changes separate from the macOS/path fixes so each issue group can be reviewed and merged independently.