Add GeoIP lookup support and update device fingerprints to base58

- Add maxmind library for GeoIP database lookups when not behind Cloudflare
- Extract client IP from multiple header sources (CF, X-Real-IP, X-Forwarded-For, etc.)
- Change device fingerprints from UUID to base58 with device_ prefix
- Add isValidDeviceFingerprint() that accepts both new and legacy formats
- Colocate unit tests with source files, remove __tests__/unit directory
- Add test coverage reporting to test script

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/api-server/src/utils/crypto.ts

@@ -1,7 +1,8 @@
+import { generateSecureBase58Token } from "@reviq/utils";
 import { base58 } from "@scure/base";
 
-// Re-export generateSecureBase58Token from shared utils
-export { generateSecureBase58Token } from "@reviq/utils";
+// Re-export for convenience
+export { generateSecureBase58Token };
 
 /**
  * Token prefix for all RevIQ API tokens
@@ -59,10 +60,40 @@ export const generateSessionToken = (): string => {
 };
 
 /**
- * Generate a device fingerprint (UUID v4)
+ * Device fingerprint prefix for new fingerprints
+ */
+export const DEVICE_FINGERPRINT_PREFIX = "device_";
+
+/**
+ * Generate a device fingerprint (base58 with device_ prefix)
  */
 export const generateDeviceFingerprint = (): string => {
-  return crypto.randomUUID();
+  return generateSecureBase58Token(DEVICE_FINGERPRINT_PREFIX);
+};
+
+/**
+ * Check if a string is a valid device fingerprint.
+ * Accepts both new format (device_ prefix) and legacy UUIDs.
+ */
+export const isValidDeviceFingerprint = (fingerprint: string): boolean => {
+  // New format: device_ prefix with base58
+  if (fingerprint.startsWith(DEVICE_FINGERPRINT_PREFIX)) {
+    const base58Part = fingerprint.slice(DEVICE_FINGERPRINT_PREFIX.length);
+    if (base58Part.length === 0) {
+      return false;
+    }
+    try {
+      base58.decode(base58Part);
+      return true;
+    } catch {
+      return false;
+    }
+  }
+
+  // Legacy format: UUID v4
+  const uuidRegex =
+    /^[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i;
+  return uuidRegex.test(fingerprint);
 };
 
 /**