fix: OAuth token endpoint wraps in {code,message,data} — not flat

The /authen/v1/oidc/access_token response uses the standard Feishu envelope
with 'message' (not 'msg') field. Updated FeishuAPIResponse to handle both
'msg' and 'message' via custom init(from:). exchangeCode and
refreshAccessToken now decode via FeishuAPIResponse<OAuthTokenData>.

Tenant token endpoint (/auth/v3/tenant_access_token/internal) returns flat
response — TenantAccessTokenData decoded directly.

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

Sources/Services/Feishu/FeishuAuthService.swift

@@ -50,11 +50,14 @@ final class FeishuAuthService {
         request.httpMethod = "POST"
         request.setValue("application/json; charset=utf-8", forHTTPHeaderField: "Content-Type")
         request.setValue("Bearer \(tenantToken)", forHTTPHeaderField: "Authorization")
-        // Use manual JSON to rule out JSONEncoder issues
         let jsonBody = "{\"grant_type\":\"authorization_code\",\"code\":\"\(code)\"}"
         request.httpBody = jsonBody.data(using: .utf8)
         print("[BUGGER] exchangeCode: sending to \(url.absoluteString)...")
-        let tokenData: OAuthTokenData = try await send(request)
+        // OAuth token response is wrapped in {code, message, data: {...}}
+        let response: FeishuAPIResponse<OAuthTokenData> = try await send(request)
+        guard response.code == 0, let tokenData = response.data else {
+            throw FeishuError.apiError(code: response.code, message: response.msg)
+        }
         print("[BUGGER] exchangeCode: SUCCESS access=\(tokenData.accessToken.prefix(8))... refresh=\(tokenData.refreshToken?.prefix(8) ?? "nil")...")
         return tokenData
     }
@@ -66,12 +69,13 @@ final class FeishuAuthService {
         request.httpMethod = "POST"
         request.setValue("application/json; charset=utf-8", forHTTPHeaderField: "Content-Type")
         request.setValue("Bearer \(tenantToken)", forHTTPHeaderField: "Authorization")
-        request.httpBody = try JSONEncoder().encode([
+        let jsonBody = "{\"grant_type\":\"refresh_token\",\"refresh_token\":\"\(refreshToken)\"}"
-            "grant_type": "refresh_token",
+        request.httpBody = jsonBody.data(using: .utf8)
-            "refresh_token": refreshToken,
+        // Uses same {code, message, data: {...}} wrapper as exchangeCode
-        ] as [String: String])
+        let response: FeishuAPIResponse<OAuthTokenData> = try await send(request)
-        // Token endpoints return data at top level, not wrapped in {code, msg, data}
+        guard response.code == 0, let tokenData = response.data else {
-        let tokenData: OAuthTokenData = try await send(request)
+            throw FeishuError.apiError(code: response.code, message: response.msg)
+        }
         return tokenData
     }
 

Sources/Services/Feishu/FeishuModels.swift

@@ -4,6 +4,22 @@ struct FeishuAPIResponse<T: Decodable>: Decodable {
     let code: Int
     let msg: String
     let data: T?
+
+    enum CodingKeys: String, CodingKey {
+        case code, msg, message, data
+    }
+
+    init(from decoder: Decoder) throws {
+        let c = try decoder.container(keyedBy: CodingKeys.self)
+        code = try c.decode(Int.self, forKey: .code)
+        // Some endpoints use "msg", others use "message"
+        if let m = try c.decodeIfPresent(String.self, forKey: .msg) {
+            msg = m
+        } else {
+            msg = try c.decode(String.self, forKey: .message)
+        }
+        data = try c.decodeIfPresent(T.self, forKey: .data)
+    }
 }
 
 struct RecordListData: Decodable {