feat: support private repo cloning with HTTP basic auth

- Add SSH URL detection with friendly prompt to use HTTPS instead
- Add private repo toggle (default off) with username/password fields
- Persist auth_type and credential in repositories table
- Pass stored credentials to PullRepo for authenticated pulls
- Incremental migration adds auth_type and credential columns

templates/pages/index.html

@@ -14,13 +14,31 @@
             <!-- Clone Form -->
             <div class="bg-white rounded-lg shadow-sm border border-gray-200 p-6 mb-8">
                 <h2 class="text-lg font-semibold mb-4">克隆仓库</h2>
-                <form id="clone-form" class="flex gap-3">
-                    <input type="text" id="repo-url" name="url" placeholder="https://github.com/user/repo.git"
-                           class="flex-1 rounded-md border border-gray-300 px-3 py-2 text-sm focus:outline-none focus:ring-2 focus:ring-indigo-500 focus:border-indigo-500" required>
-                    <button type="submit" id="clone-btn"
-                            class="bg-indigo-600 text-white px-5 py-2 rounded-md text-sm font-medium hover:bg-indigo-700 focus:outline-none focus:ring-2 focus:ring-indigo-500 focus:ring-offset-2">
-                        克隆
-                    </button>
+                <form id="clone-form" class="space-y-3">
+                    <div class="flex gap-3">
+                        <input type="text" id="repo-url" name="url" placeholder="https://github.com/user/repo.git"
+                               class="flex-1 rounded-md border border-gray-300 px-3 py-2 text-sm focus:outline-none focus:ring-2 focus:ring-indigo-500 focus:border-indigo-500" required>
+                        <button type="submit" id="clone-btn"
+                                class="bg-indigo-600 text-white px-5 py-2 rounded-md text-sm font-medium hover:bg-indigo-700 focus:outline-none focus:ring-2 focus:ring-indigo-500 focus:ring-offset-2">
+                            克隆
+                        </button>
+                    </div>
+                    <div id="ssh-warning" class="hidden rounded-md bg-yellow-50 border border-yellow-200 px-4 py-3 text-sm text-yellow-800">
+                        检测到 SSH 格式地址，请使用 HTTPS 格式。例如：<code class="bg-yellow-100 px-1 rounded">https://github.com/user/repo.git</code>
+                    </div>
+                    <div class="flex items-center gap-2">
+                        <label class="relative inline-flex items-center cursor-pointer">
+                            <input type="checkbox" id="private-toggle" class="sr-only peer">
+                            <div class="w-9 h-5 bg-gray-200 peer-focus:outline-none peer-focus:ring-2 peer-focus:ring-indigo-300 rounded-full peer peer-checked:after:translate-x-full peer-checked:after:border-white after:content-[''] after:absolute after:top-[2px] after:left-[2px] after:bg-white after:border-gray-300 after:border after:rounded-full after:h-4 after:w-4 after:transition-all peer-checked:bg-indigo-600"></div>
+                        </label>
+                        <span class="text-sm text-gray-600">私有仓库</span>
+                    </div>
+                    <div id="auth-fields" class="hidden grid grid-cols-2 gap-3">
+                        <input type="text" id="repo-username" placeholder="用户名（可选）"
+                               class="rounded-md border border-gray-300 px-3 py-2 text-sm focus:outline-none focus:ring-2 focus:ring-indigo-500 focus:border-indigo-500">
+                        <input type="password" id="repo-password" placeholder="密码或 Personal Access Token"
+                               class="rounded-md border border-gray-300 px-3 py-2 text-sm focus:outline-none focus:ring-2 focus:ring-indigo-500 focus:border-indigo-500">
+                    </div>
                 </form>
                 <div id="clone-progress" class="hidden mt-4">
                     <div class="flex items-center gap-3 mb-2">
@@ -74,10 +92,30 @@
     {{template "footer" .}}
 </div>
 <script>
+// Toggle private repo auth fields
+document.getElementById('private-toggle').addEventListener('change', function() {
+    document.getElementById('auth-fields').classList.toggle('hidden', !this.checked);
+});
+
+// Detect SSH URLs on input
+document.getElementById('repo-url').addEventListener('input', function() {
+    const val = this.value.trim();
+    const isSSH = /^(git@|ssh:\/\/)/.test(val);
+    document.getElementById('ssh-warning').classList.toggle('hidden', !isSSH);
+});
+
 document.getElementById('clone-form').addEventListener('submit', async function(e) {
     e.preventDefault();
     const url = document.getElementById('repo-url').value.trim();
     if (!url) return;
+
+    // Block SSH URLs
+    if (/^(git@|ssh:\/\/)/.test(url)) {
+        const sshWarn = document.getElementById('ssh-warning');
+        sshWarn.classList.remove('hidden');
+        return;
+    }
+
     const btn = document.getElementById('clone-btn');
     const progress = document.getElementById('clone-progress');
     const status = document.getElementById('clone-status');
@@ -90,12 +128,16 @@ document.getElementById('clone-form').addEventListener('submit', async function(
     bar.style.width = '0%';
     status.textContent = '正在连接...';
 
+    const isPrivate = document.getElementById('private-toggle').checked;
+    const username = isPrivate ? document.getElementById('repo-username').value.trim() : '';
+    const password = isPrivate ? document.getElementById('repo-password').value : '';
+
     try {
         const resp = await fetch('/api/repos', {
             method: 'POST',
             headers: {'Content-Type': 'application/json'},
             credentials: 'same-origin',
-            body: JSON.stringify({url: url})
+            body: JSON.stringify({url, username, password})
         });
 
         if (!resp.ok) {