feat(cli): Add deterministic detect command for rule routing

[thecodedrift]

Add taskless detect --json: an offline, deterministic scan of the working directory that emits the signals the routing recipes consume.

It reports configured linters (evidenced by config files, pyproject.toml [tool.x] tables, or package.json dependencies), inferred languages and frameworks, and the styles of the repo's own existing rules. There is no LLM, no network, and no auth — the command is a stable, testable input that keeps the routing agent from hallucinating the repo's tooling.

By design, detect reports only repo signals; it never matches a request against a catalog of packaged rules. That judgment is effectively infinite across ecosystems and is left to the existing recipe (repo + WebFetch), not baked into the CLI.

Implementation is a focused scanner module (detect/scan.ts) behind a thin command, a Zod output schema, and integration tests covering linter detection across eslint/ruff/rubocop/biome/stylelint, language/framework inference, the no-packaged-rule-claims contract, and the offline/no-auth guarantee.

Stacked on #23 (the change contract). Review/merge that first.

Refs TSKL Runtime Rules

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• main
  • docs(openspec): Propose local-rule-routing change #23
    • feat(cli): Add deterministic detect command for rule routing 👈
      • feat(cli): Add route/existing/static/remote authoring recipes #25
        • feat(cli): Surface routing recipes in the help index #26
          • feat(skill): Engage routing when a linter is named #27
            • test(cli): Add route honesty eval fixtures and finalize change #28

^{Stack generated by Git Town}

[Copilot]

Pull request overview

Adds a new taskless detect subcommand intended to provide a deterministic, offline JSON “repo signals” scan that downstream rule-routing recipes can consume (linters, languages/frameworks, and existing local rule styles).

Changes:

• Introduces a filesystem-only repository scanner (packages/cli/src/detect/scan.ts) to infer linters, languages/frameworks, and local rule style signals.
• Adds a detect CLI command with --json output and registers it in the CLI entrypoint.
• Adds Vitest integration tests for linter detection, language/framework inference, rule-style surfacing, and stable JSON shape.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
packages/cli/test/detect.test.ts	New integration tests that execute the built CLI and validate detect JSON signals.
packages/cli/src/schemas/detect.ts	New Zod schema describing taskless detect --json output.
packages/cli/src/index.ts	Registers the new detect subcommand.
packages/cli/src/detect/scan.ts	Implements deterministic repo signal scanning for linters/languages/frameworks/rule styles.
packages/cli/src/commands/detect.ts	Adds the detect CLI command and JSON/human output modes.
openspec/changes/local-rule-routing/tasks.md	Adds/updates spec task tracking for the local-rule-routing change set.

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