feat: command refactor

[BCsabaEngine]

No description provided.

[Copilot]

Pull request overview

This PR refactors the CLI from a flag-driven interface into explicit subcommands (run, diff, validate, format, suggest, list-files, show-config), updates the main orchestrator and tests accordingly, and refreshes docs/examples to match the new command structure.

Changes:

• Refactor CLI parsing to Commander subcommands and update unit tests to assert per-command option sets.
• Update runtime flow in src/index.ts to branch on commandName (new early exits, new diff command path, validate --strict exit code).
• Update README/FAQ/CONTRIBUTING/CLAUDE and example docs/scripts to the new CLI usage; bump @typescript-eslint/eslint-plugin.

Reviewed changes

Copilot reviewed 19 out of 20 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
test/commandLine.test.ts	Reworks CLI parsing tests around new subcommands and option sets.
src/index.ts	Switches orchestration logic to commandName; adds strict validation exit code handling and new diff behavior.
src/exitCodes.ts	Adds EXIT_VALIDATION_WARNINGS for validate --strict.
src/commandLine.ts	Implements Commander subcommands and shared option parsing/validation helpers.
package.json	Bumps @typescript-eslint/eslint-plugin patch version.
package-lock.json	Lockfile updates for the eslint-plugin bump and related packages.
example/7-format-only/config.yaml	Updates usage comment to new format command.
example/7-format-only/README.md	Updates format-only example commands to subcommand syntax.
example/5-external-files/README.md	Updates usage snippets to new diff/run/validate/list-files commands.
example/4-prune-mode/README.md	Updates usage snippets to new diff/run commands and wording.
example/3-multi-env-chain/sync-all.sh	Updates scripted invocations to diff (preview) and run (apply).
example/3-multi-env-chain/README.md	Updates walkthrough commands to diff and run.
example/2-stop-rules/README.md	Updates stop-rule example commands to diff and run.
example/1-config-inheritance/README.md	Updates inheritance example commands to diff and run.
example/0-basic/config-minimal.yaml	Updates comment to refer to suggest command wording.
example/0-basic/README.md	Updates basic example commands to diff/run.
README.md	Major documentation rewrite for subcommands, options tables, examples, and new exit code 4.
FAQ.md	Updates FAQ guidance/examples to subcommands and documents validate --strict.
CONTRIBUTING.md	Updates repo layout, scripts, test commands, architecture notes, and exit codes section.
CLAUDE.md	Updates CLI and architecture notes to subcommands and strict validation exit code.

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