chore: add engineering improvements

- Configure Prettier with unified code style rules
- Add husky + lint-staged for automated pre-commit checks
- Add commitlint to enforce conventional commit messages
- Add PR check workflow for CI automation
- Auto-format all files with Prettier
- Fix TypeScript any types in field-crypto.ts

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

src/backend/utils/field-crypto.ts

@@ -27,12 +27,7 @@ class FieldCrypto {
       "oidc_identifier",
       "oidcIdentifier",
     ]),
-    ssh_data: new Set([
-      "password",
-      "key",
-      "key_password",
-      "keyPassword",
-    ]),
+    ssh_data: new Set(["password", "key", "key_password", "keyPassword"]),
     ssh_credentials: new Set([
       "password",
       "private_key",
@@ -60,7 +55,11 @@ class FieldCrypto {
     );
 
     const iv = crypto.randomBytes(this.IV_LENGTH);
-    const cipher = crypto.createCipheriv(this.ALGORITHM, fieldKey, iv) as any;
+    const cipher = crypto.createCipheriv(
+      this.ALGORITHM,
+      fieldKey,
+      iv,
+    ) as crypto.CipherGCM;
 
     let encrypted = cipher.update(plaintext, "utf8", "hex");
     encrypted += cipher.final("hex");
@@ -102,7 +101,7 @@ class FieldCrypto {
       this.ALGORITHM,
       fieldKey,
       Buffer.from(encrypted.iv, "hex"),
-    ) as any;
+    ) as crypto.DecipherGCM;
     decipher.setAuthTag(Buffer.from(encrypted.tag, "hex"));
 
     let decrypted = decipher.update(encrypted.data, "hex", "utf8");