fix: resolve CVEs, upgrade to Astro v6, and harden API security (#227)

* fix: resolve CVEs, upgrade to Astro v6, and harden API security

Docker image CVE fixes:
- Install git-lfs v3.7.1 from GitHub releases (Go 1.25) instead of
  Debian apt (Go 1.23.12), fixing CVE-2025-68121 and 8 other Go stdlib CVEs
- Strip build-only packages (esbuild, vite, rollup, svgo, tailwindcss)
  from production image, eliminating 9 esbuild Go stdlib CVEs

Dependency upgrades:
- Astro v5 → v6 (includes Vite 7, Zod 4)
- Remove legacy content config (src/content/config.ts)
- Update HealthResponse type for simplified health endpoint
- npm overrides for fast-xml-parser ≥5.3.6, devalue ≥5.6.2,
  node-forge ≥1.3.2, svgo ≥4.0.1, rollup ≥4.59.0

API security hardening:
- /api/auth/debug: dev-only, require auth, remove user-creation POST,
  strip trustedOrigins/databaseConfig from response
- /api/auth/check-users: return boolean hasUsers instead of exact count
- /api/cleanup/auto: require authentication, remove per-user details
- /api/health: remove OS version, memory, uptime from response
- /api/config: validate Gitea URL protocol (http/https only)
- BETTER_AUTH_SECRET: log security warning when using insecure defaults
- generateRandomString: replace Math.random() with crypto.getRandomValues()
- hashValue: add random salt and timing-safe verification

* repositories: migrate table to tanstack

* Revert "repositories: migrate table to tanstack"

This reverts commit a544b29e6d.

* fixed lock file

src/lib/utils/encryption.ts

@@ -160,10 +160,23 @@ export function generateSecureToken(length: number = 32): string {
 }
 
 /**
- * Hashes a value using SHA-256 (for non-reversible values like API keys for comparison)
+ * Hashes a value using SHA-256 with a random salt (for non-reversible values like API keys)
  * @param value The value to hash
- * @returns Hex encoded hash
+ * @returns Salt and hash in format "salt:hash"
  */
 export function hashValue(value: string): string {
-  return crypto.createHash('sha256').update(value).digest('hex');
+  const salt = crypto.randomBytes(16).toString('hex');
+  const hash = crypto.createHash('sha256').update(salt + value).digest('hex');
+  return `${salt}:${hash}`;
+}
+
+/**
+ * Verifies a value against a salted hash produced by hashValue()
+ * Uses constant-time comparison to prevent timing attacks
+ */
+export function verifyHash(value: string, saltedHash: string): boolean {
+  const [salt, expectedHash] = saltedHash.split(':');
+  if (!salt || !expectedHash) return false;
+  const actualHash = crypto.createHash('sha256').update(salt + value).digest('hex');
+  return crypto.timingSafeEqual(Buffer.from(actualHash, 'hex'), Buffer.from(expectedHash, 'hex'));
 }