feat: implement proto-gen platform

- Config loader with env var expansion and validation
- SQLite database with tasks and toolchain_versions tables
- Gitea REST API client for repository and branch operations
- K8s client for Job lifecycle management (with noop fallback for local dev)
- REST API: tasks CRUD, retry, plugins, version management
- Worker/scheduler with polling, concurrency control, and job tracking
- Static frontend: generate, tasks, settings pages
- Toolchain images: Go and Node.js Dockerfiles with entrypoint scripts
- Helm chart with deployment, service, configmap, ingress, PVC
- Multi-stage Dockerfile for service
- Unit tests for config, database, gitclient, k8s, api, worker
- E2E tests for idempotency, version switch, failure recovery

internal/static/app.js

@@ -0,0 +1,141 @@
+const API_BASE = '/api/v1';
+
+async function api(method, path, body) {
+    const options = {
+        method,
+        headers: { 'Content-Type': 'application/json' }
+    };
+    if (body) options.body = JSON.stringify(body);
+    const res = await fetch(API_BASE + path, options);
+    if (!res.ok) {
+        const err = await res.json();
+        throw new Error(err.error || 'Request failed');
+    }
+    return res.json();
+}
+
+function showMessage(text, type = 'success') {
+    const msg = document.getElementById('message');
+    if (!msg) return;
+    msg.textContent = text;
+    msg.className = `message ${type}`;
+    setTimeout(() => msg.className = 'hidden', 5000);
+}
+
+function formatDate(dateStr) {
+    if (!dateStr) return '-';
+    return new Date(dateStr).toLocaleString();
+}
+
+function statusBadge(status) {
+    const colors = {
+        pending: '#f39c12',
+        running: '#3498db',
+        success: '#27ae60',
+        failed: '#e74c3c'
+    };
+    return `<span class="badge" style="background:${colors[status] || '#999'}">${status}</span>`;
+}
+
+async function initGeneratePage() {
+    try {
+        const plugins = await api('GET', '/plugins');
+        const select = document.getElementById('language');
+        plugins.forEach(p => {
+            const opt = document.createElement('option');
+            opt.value = p.language;
+            opt.textContent = p.language;
+            select.appendChild(opt);
+        });
+    } catch (e) {
+        console.error('Failed to load plugins:', e);
+    }
+
+    document.getElementById('generateForm').addEventListener('submit', async (e) => {
+        e.preventDefault();
+        const btn = e.target.querySelector('button[type="submit"]');
+        btn.disabled = true;
+        btn.textContent = 'Generating...';
+
+        try {
+            const task = await api('POST', '/tasks', {
+                language: document.getElementById('language').value,
+                proto_repo: document.getElementById('protoRepo').value,
+                proto_branch: document.getElementById('protoBranch').value,
+                target_repo: document.getElementById('targetRepo').value || undefined
+            });
+            showMessage(`Task created: ${task.id}`, 'success');
+            e.target.reset();
+            document.getElementById('protoBranch').value = 'main';
+        } catch (err) {
+            showMessage(err.message, 'error');
+        } finally {
+            btn.disabled = false;
+            btn.textContent = 'Generate';
+        }
+    });
+}
+
+async function initTasksPage() {
+    await refreshTasks();
+    document.getElementById('statusFilter').addEventListener('change', refreshTasks);
+    setInterval(refreshTasks, 10000);
+}
+
+async function refreshTasks() {
+    const status = document.getElementById('statusFilter').value;
+    const params = status ? `?status=${status}` : '';
+    try {
+        const tasks = await api('GET', `/tasks${params}`);
+        const tbody = document.getElementById('tasksBody');
+        const noTasks = document.getElementById('noTasks');
+
+        if (!tasks || tasks.length === 0) {
+            tbody.innerHTML = '';
+            noTasks.classList.remove('hidden');
+            return;
+        }
+
+        noTasks.classList.add('hidden');
+        tbody.innerHTML = tasks.map(t => `
+            <tr>
+                <td><code>${t.id.substring(0, 8)}</code></td>
+                <td>${t.language}</td>
+                <td>${t.proto_repo}</td>
+                <td>${t.target_repo}</td>
+                <td>${statusBadge(t.status)}</td>
+                <td>${formatDate(t.created_at)}</td>
+                <td>
+                    ${t.status === 'failed' ? `<button onclick="retryTask('${t.id}')" class="btn-small">Retry</button>` : ''}
+                </td>
+            </tr>
+        `).join('');
+    } catch (err) {
+        console.error('Failed to load tasks:', err);
+    }
+}
+
+async function retryTask(id) {
+    try {
+        await api('POST', `/tasks/${id}/retry`);
+        showMessage('Task queued for retry');
+        refreshTasks();
+    } catch (err) {
+        showMessage(err.message, 'error');
+    }
+}
+
+async function initSettingsPage() {
+    try {
+        const plugins = await api('GET', '/plugins');
+        const container = document.getElementById('pluginsList');
+        container.innerHTML = plugins.map(p => `
+            <div class="plugin-card">
+                <h3>${p.language}</h3>
+                <p>Image: <code>${p.image}</code></p>
+            </div>
+        `).join('');
+    } catch (err) {
+        console.error('Failed to load plugins:', err);
+    }
+}