Add impeccable CLI with detect subcommand

Usage: npx impeccable detect [file-or-dir-or-url...]

Subcommand structure designed for future expansion. The detect
subcommand delegates to the existing detection engine with all
its modes (jsdom, regex, Puppeteer).

- bin/impeccable.mjs: CLI entry point with bun shebang
- package.json: bin field added
- Export detectCli (main) from detection script
- Updated help text to show impeccable detect usage
- Updated CLAUDE.md and README.md with CLI docs

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

package.json

@@ -2,6 +2,9 @@
   "name": "impeccable",
   "version": "1.5.1",
   "author": "Paul Bakaus",
+  "bin": {
+    "impeccable": "./bin/impeccable.mjs"
+  },
   "dependencies": {
     "archiver": "^7.0.1",
     "motion": "^12.38.0",