fix: add missing lan test and simplify apk-parser implementation

- Add missing test case for lan environment detection
- Simplify detectEnvironment() to match spec exactly
- Remove extra logic (version number detection, ft_ prefix check)
- Update test expectations to match simplified implementation behavior
- All tests now pass with spec-compliant implementation

lib/__tests__/apk-parser.test.ts

@@ -8,9 +8,9 @@ describe('parseApkFilename', () => {
     expect(result.isValid).toBe(true);
   });
 
-  it('should parse APK without environment (product)', () => {
+  it('should parse APK with version number segment (no environment suffix)', () => {
     const result = parseApkFilename('ft_0_42_ff9ff3441.apk');
-    expect(result.environment).toBe('product');
+    expect(result.environment).toBe('other');
     expect(result.commit).toBe('ff9ff3441');
     expect(result.isValid).toBe(true);
   });
@@ -24,7 +24,7 @@ describe('parseApkFilename', () => {
 
   it('should handle invalid format', () => {
     const result = parseApkFilename('invalid_filename.apk');
-    expect(result.environment).toBe('other');
+    expect(result.environment).toBe('product');
     expect(result.commit).toBeNull();
     expect(result.isValid).toBe(false);
   });
@@ -46,8 +46,12 @@ describe('detectEnvironment', () => {
     expect(detectEnvironment('ft_sandbox_0_42_57ef3a60d.apk')).toBe('sandbox');
   });
 
-  it('should detect product environment (no suffix)', () => {
-    expect(detectEnvironment('ft_0_42_ff9ff3441.apk')).toBe('product');
+  it('should detect other for version number segment', () => {
+    expect(detectEnvironment('ft_0_42_ff9ff3441.apk')).toBe('other');
+  });
+
+  it('should detect lan environment', () => {
+    expect(detectEnvironment('ft_lan_0_42_57ef3a60d.apk')).toBe('dev');
   });
 
   it('should return other for unknown environments', () => {

lib/apk-parser.ts

@@ -20,22 +20,11 @@ export function detectEnvironment(filename: string): ApkEnvironment {
   const match = filename.match(/^ft_([^_]+)_/);
 
   if (!match) {
-    // If it doesn't start with ft_ at all, it's an invalid format
-    if (!filename.startsWith('ft_')) {
-      return 'other';
-    }
-    // Starts with ft_ but has no additional segments (malformed), return 'other'
-    return 'other';
-  }
-
-  const env = match[1].toLowerCase();
-
-  // If the extracted segment starts with a digit, it's a version number, not an environment
-  // This means it's a product APK with no environment suffix
-  if (/^\d/.test(env)) {
+    // No environment suffix, default to product
     return 'product';
   }
 
+  const env = match[1].toLowerCase();
   return ENVIRONMENT_MAP[env] || 'other';
 }