feat(release): add @hanzo/dev npm package publishing

Create parallel dev-cli/ package structure for @hanzo/dev npm distribution:
- Add bin/dev.js entry point that resolves platform binary
- Add postinstall.js for binary download on install
- Add scripts/preinstall.js for Windows cleanup
- Add scripts/windows-cleanup.ps1 PowerShell helper

Update release workflow to:
- Create @hanzo/dev-* platform packages alongside @just-every/code-*
- Rename code-* binaries to dev-* in @hanzo/dev packages
- Update dev-cli/package.json with version and optionalDependencies
- Publish @hanzo/dev main package to npm

This fixes the broken @hanzo/dev npm package which was missing
platform binary packages (@hanzo/dev-darwin-arm64, etc.)

dev-cli/scripts/preinstall.js

@@ -0,0 +1,69 @@
+#!/usr/bin/env node
+// Windows-friendly preinstall: proactively free file locks from prior installs
+// so npm/yarn/pnpm can stage the new package. No-ops on non-Windows.
+
+import { platform } from 'os';
+import { execSync } from 'child_process';
+import { existsSync, readdirSync, rmSync, readFileSync, statSync } from 'fs';
+import path from 'path';
+import { fileURLToPath } from 'url';
+
+function isWSL() {
+  if (platform() !== 'linux') return false;
+  try {
+    const rel = readFileSync('/proc/version', 'utf8').toLowerCase();
+    return rel.includes('microsoft') || !!process.env.WSL_DISTRO_NAME;
+  } catch { return false; }
+}
+
+const isWin = platform() === 'win32';
+const wsl = isWSL();
+const isWinLike = isWin || wsl;
+
+// Scope: only run for global installs, unless explicitly forced. Allow opt-out.
+const isGlobal = process.env.npm_config_global === 'true';
+const force = process.env.DEV_FORCE_PREINSTALL === '1';
+const skip = process.env.DEV_SKIP_PREINSTALL === '1';
+if (!isWinLike || skip || (!isGlobal && !force)) process.exit(0);
+
+function tryExec(cmd, opts = {}) {
+  try { execSync(cmd, { stdio: ['ignore', 'ignore', 'ignore'], shell: true, ...opts }); } catch { /* ignore */ }
+}
+
+// 1) Stop our native binary if it is holding locks. Avoid killing unrelated tools.
+// Only available on native Windows; skip entirely on WSL to avoid noise.
+if (isWin) {
+  tryExec('taskkill /IM dev-x86_64-pc-windows-msvc.exe /F');
+}
+
+// 2) Remove stale staging dirs from previous failed installs under the global
+//    @hanzo scope, which npm will reuse (e.g., .dev-XXXXX). Remove only
+//    old entries and never the current staging or live package.
+try {
+  let scopeDir = '';
+  try {
+    const root = execSync('npm root -g', { stdio: ['ignore', 'pipe', 'ignore'], shell: true }).toString().trim();
+    scopeDir = path.join(root, '@hanzo');
+  } catch {
+    // Fall back to guessing from this script location: <staging>\..\..\
+    const here = path.resolve(path.dirname(fileURLToPath(import.meta.url)));
+    scopeDir = path.resolve(here, '..');
+  }
+  if (existsSync(scopeDir)) {
+    const now = Date.now();
+    const maxAgeMs = 2 * 60 * 60 * 1000; // 2 hours
+    const currentDir = path.resolve(path.dirname(fileURLToPath(import.meta.url)), '..');
+    for (const name of readdirSync(scopeDir)) {
+      if (!name.startsWith('.dev-')) continue;
+      const p = path.join(scopeDir, name);
+      if (path.resolve(p) === currentDir) continue; // never remove our current dir
+      try {
+        const st = statSync(p);
+        const age = now - st.mtimeMs;
+        if (age > maxAgeMs) rmSync(p, { recursive: true, force: true });
+      } catch { /* ignore */ }
+    }
+  }
+} catch { /* ignore */ }
+
+process.exit(0);

dev-cli/scripts/windows-cleanup.ps1

@@ -0,0 +1,31 @@
+<#
+Helper to recover from EBUSY/EPERM during global npm upgrades on Windows.
+Closes running processes and removes stale package folders.
+
+Usage (PowerShell):
+  Set-ExecutionPolicy -Scope Process Bypass -Force
+  ./dev-cli/scripts/windows-cleanup.ps1
+#>
+
+$ErrorActionPreference = 'SilentlyContinue'
+
+Write-Host "Stopping running Hanzo Dev processes..."
+taskkill /IM dev-x86_64-pc-windows-msvc.exe /F 2>$null | Out-Null
+taskkill /IM dev.exe /F 2>$null | Out-Null
+taskkill /IM hanzo.exe /F 2>$null | Out-Null
+
+Write-Host "Removing old global package (if present)..."
+$npmRoot = (& npm root -g).Trim()
+$pkgPath = Join-Path $npmRoot "@hanzo\dev"
+if (Test-Path $pkgPath) {
+  try { Remove-Item -LiteralPath $pkgPath -Recurse -Force -ErrorAction Stop } catch {}
+}
+
+Write-Host "Removing temp staging directories (if present)..."
+Get-ChildItem -LiteralPath (Join-Path $npmRoot "@hanzo") -Force -ErrorAction SilentlyContinue |
+  Where-Object { $_.Name -like '.dev-*' } |
+  ForEach-Object {
+    try { Remove-Item -LiteralPath $_.FullName -Recurse -Force -ErrorAction Stop } catch {}
+  }
+
+Write-Host "Cleanup complete. You can now run: npm install -g @hanzo/dev@latest"