feat: add APK filename parser utilities

- Add detectEnvironment() to parse environment from APK filenames
- Add parseApkFilename() to extract environment and commit ID metadata
- Support dev, sandbox, product, and other environment types
- Map environment patterns: timeshift, lan, dev -> dev; sandbox -> sandbox
- Detect product APKs when no environment suffix present
- Handle invalid formats gracefully

lib/apk-parser.ts

@@ -0,0 +1,53 @@
+export type ApkEnvironment = 'dev' | 'sandbox' | 'product' | 'other';
+
+export interface ParsedApkMetadata {
+  environment: ApkEnvironment;
+  commit: string | null;
+  isValid: boolean;
+}
+
+// Environment mapping based on filename patterns
+const ENVIRONMENT_MAP: Record<string, ApkEnvironment> = {
+  'timeshift': 'dev',
+  'lan': 'dev',
+  'dev': 'dev',
+  'sandbox': 'sandbox',
+};
+
+export function detectEnvironment(filename: string): ApkEnvironment {
+  // Pattern: ft_[environment]_version_commit.apk
+  // Extract the environment segment between first and second underscores
+  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)) {
+    return 'product';
+  }
+
+  return ENVIRONMENT_MAP[env] || 'other';
+}
+
+export function parseApkFilename(filename: string): ParsedApkMetadata {
+  const environment = detectEnvironment(filename);
+  const commitMatch = filename.match(/([a-f0-9]{7,})\.apk$/);
+  const commit = commitMatch ? commitMatch[1] : null;
+  const isValid = commit !== null;
+
+  return {
+    environment,
+    commit,
+    isValid,
+  };
+}