feat(admin): add system status panel with database, storage, and update checks

Add a comprehensive System Status page to the admin panel that provides
actionable insights for administrators to monitor their Umami instance health.

Features:
- Database connectivity check with connection status and database type
- Storage usage monitoring with total, used, and free space display
  - Visual progress bar with color-coded warnings (75% and 90% thresholds)
  - Human-readable byte formatting
  - Fallback support for different filesystem types
- Update notifications with version comparison using semver
  - Current version display
  - Latest version check via Umami API
  - Clear update availability indicators

Technical details:
- New API endpoint: /api/admin/status (admin-only access)
- New admin page: /admin/status
- Added to admin navigation menu with Activity icon
- Auto-refreshes every 60 seconds
- Proper error handling and graceful degradation
- Uses existing permission system (canViewUsers check)
- Follows existing UI patterns and component structure
- Added i18n labels: systemStatus, database, storage, updates

This addresses the need for administrators to have visibility into system
health and proactively identify potential issues before they impact users.

src/app/api/admin/status/route.ts

@@ -0,0 +1,234 @@
+import { parseRequest } from '@/lib/request';
+import { json, unauthorized } from '@/lib/response';
+import { canViewUsers } from '@/permissions';
+import prisma from '@/lib/prisma';
+import { CURRENT_VERSION, UPDATES_URL } from '@/lib/constants';
+import { execSync } from 'node:child_process';
+import { existsSync } from 'node:fs';
+import { join } from 'node:path';
+import { statfs } from 'node:fs/promises';
+import semver from 'semver';
+
+interface DatabaseStatus {
+  connected: boolean;
+  type: string;
+  error?: string;
+}
+
+interface StorageStatus {
+  available: boolean;
+  total: number;
+  free: number;
+  used: number;
+  percentage: number;
+  path: string;
+  error?: string;
+}
+
+interface UpdateStatus {
+  current: string;
+  latest?: string;
+  updateAvailable: boolean;
+  error?: string;
+}
+
+interface SystemStatus {
+  database: DatabaseStatus;
+  storage: StorageStatus;
+  updates: UpdateStatus;
+}
+
+async function checkDatabase(): Promise<DatabaseStatus> {
+  try {
+    const dbType = process.env.DATABASE_TYPE || 'postgresql';
+    
+    // Try to connect and run a simple query
+    await prisma.client.$queryRaw`SELECT 1`;
+    
+    return {
+      connected: true,
+      type: dbType,
+    };
+  } catch (error: any) {
+    return {
+      connected: false,
+      type: process.env.DATABASE_TYPE || 'unknown',
+      error: error.message || 'Database connection failed',
+    };
+  }
+}
+
+async function checkStorage(): Promise<StorageStatus> {
+  try {
+    // Try to check storage for common paths
+    const pathsToCheck = [
+      process.env.DATABASE_URL ? new URL(process.env.DATABASE_URL).pathname : null,
+      process.cwd(),
+      '/',
+    ].filter(Boolean) as string[];
+
+    let path = pathsToCheck[0];
+    
+    // For PostgreSQL, try to get the data directory
+    if (process.env.DATABASE_URL) {
+      try {
+        const dbUrl = new URL(process.env.DATABASE_URL);
+        if (dbUrl.hostname === 'localhost' || dbUrl.hostname === '127.0.0.1') {
+          // Try to get PostgreSQL data directory
+          try {
+            const pgDataDir = execSync('pg_config --sharedir', { encoding: 'utf-8', stdio: 'pipe' }).trim();
+            path = join(pgDataDir, '../data');
+          } catch {
+            // Fallback to current directory
+            path = process.cwd();
+          }
+        }
+      } catch {
+        path = process.cwd();
+      }
+    }
+
+    // Check if path exists, if not use current directory
+    if (!existsSync(path)) {
+      path = process.cwd();
+    }
+
+    let total = 0;
+    let free = 0;
+    let used = 0;
+    let percentage = 0;
+
+    try {
+      // Try to use statfs (Node.js 18.9.0+)
+      const stats = await statfs(path);
+      const blockSize = stats.bsize || 1;
+      total = stats.blocks * blockSize;
+      free = stats.bavail * blockSize;
+      used = total - free;
+      percentage = total > 0 ? Math.round((used / total) * 100) : 0;
+    } catch {
+      // Fallback: Try to use df command on Unix systems
+      try {
+        const dfOutput = execSync(`df -k "${path}"`, { encoding: 'utf-8', stdio: 'pipe' });
+        const lines = dfOutput.trim().split('\n');
+        if (lines.length > 1) {
+          const parts = lines[1].split(/\s+/);
+          if (parts.length >= 4) {
+            total = parseInt(parts[1], 10) * 1024; // Convert from KB to bytes
+            used = parseInt(parts[2], 10) * 1024;
+            free = parseInt(parts[3], 10) * 1024;
+            percentage = total > 0 ? Math.round((used / total) * 100) : 0;
+          }
+        }
+      } catch {
+        // If both methods fail, we can't determine storage
+        throw new Error('Unable to determine storage usage');
+      }
+    }
+
+    return {
+      available: true,
+      total,
+      free,
+      used,
+      percentage,
+      path,
+    };
+  } catch (error: any) {
+    return {
+      available: false,
+      total: 0,
+      free: 0,
+      used: 0,
+      percentage: 0,
+      path: process.cwd(),
+      error: error.message || 'Storage check failed',
+    };
+  }
+}
+
+async function checkUpdates(): Promise<UpdateStatus> {
+  const current = CURRENT_VERSION || 'unknown';
+  
+  try {
+    if (!UPDATES_URL) {
+      return {
+        current,
+        updateAvailable: false,
+        error: 'Updates URL not configured',
+      };
+    }
+
+    // Use the same API format as the existing version check
+    const response = await fetch(`${UPDATES_URL}?v=${current}`, {
+      method: 'GET',
+      headers: {
+        Accept: 'application/json',
+        'User-Agent': 'Umami',
+      },
+    });
+
+    if (!response.ok) {
+      // If API returns non-ok, don't treat it as an error - just show current version
+      return {
+        current,
+        updateAvailable: false,
+      };
+    }
+
+    const data = await response.json();
+    
+    // The API returns { latest, url } structure
+    const latest = data?.latest || null;
+
+    if (!latest) {
+      // If no latest version in response, just show current version without error
+      return {
+        current,
+        updateAvailable: false,
+      };
+    }
+
+    // Use semver for proper version comparison
+    const updateAvailable = semver.gt(latest, current);
+
+    return {
+      current,
+      latest,
+      updateAvailable,
+    };
+  } catch (error: any) {
+    // Network errors or other issues - show current version without alarming error
+    return {
+      current,
+      updateAvailable: false,
+    };
+  }
+}
+
+export async function GET(request: Request) {
+  const { auth, error } = await parseRequest(request);
+
+  if (error) {
+    return error();
+  }
+
+  if (!(await canViewUsers(auth))) {
+    return unauthorized();
+  }
+
+  const [database, storage, updates] = await Promise.all([
+    checkDatabase(),
+    checkStorage(),
+    checkUpdates(),
+  ]);
+
+  const status: SystemStatus = {
+    database,
+    storage,
+    updates,
+  };
+
+  return json(status);
+}
+