fix(tests): resolve 10 failing tests on Windows (#2307)

- resolve-formatter: stop findProjectRoot walk before os.homedir() to
  avoid mistaking global dotfiles (e.g. ~/.prettierrc) for a project root
- instinct-cli-projects: detect python3/python binary at runtime; skip
  gracefully when Python 3 is unavailable instead of crashing with null status
- command-registry: regenerate COMMAND-REGISTRY.json (was stale)

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

scripts/lib/resolve-formatter.js

@@ -9,6 +9,7 @@
 'use strict';
 
 const fs = require('fs');
+const os = require('os');
 const path = require('path');
 
 // ── Caches (per-process, cleared on next hook invocation) ───────────
@@ -58,8 +59,12 @@ const FORMATTER_PACKAGES = {
 function findProjectRoot(startDir) {
   if (projectRootCache.has(startDir)) return projectRootCache.get(startDir);
 
+  const homeDir = os.homedir();
   let dir = startDir;
   while (dir !== path.dirname(dir)) {
+    // Stop before checking the home directory to avoid treating global
+    // dotfiles (e.g. ~/.prettierrc) as a project root marker.
+    if (dir === homeDir) break;
     for (const marker of PROJECT_ROOT_MARKERS) {
       if (fs.existsSync(path.join(dir, marker))) {
         projectRootCache.set(startDir, dir);