refactor: 数据源菜单合一+布局优化

- 4个数据源菜单(MySQL/PG/Redis/Mongo)合并为1个「数据源」
- InstancePage 改为统一入口，顶部Tab切换类型过滤
- 添加数据源改为弹框Modal（默认MySQL）
- 去掉左下角用户区，退出登录移到右上角header
- 侧边栏收窄220px，整体布局更紧凑
- 后端202 tests passing
- 前端构建零错误

frontend/src/api/dictionary.ts

@@ -0,0 +1,22 @@
+import request from './request';
+
+export var dictionaryApi = {
+  listDatabases: function (instanceId: number) {
+    return request.get('/dictionary/instances/' + instanceId + '/databases');
+  },
+  listTables: function (instanceId: number, database: string) {
+    return request.get('/dictionary/instances/' + instanceId + '/tables', {
+      params: { database: database },
+    });
+  },
+  getTableDetail: function (instanceId: number, tableName: string, database: string) {
+    return request.get('/dictionary/instances/' + instanceId + '/tables/' + tableName, {
+      params: { database: database },
+    });
+  },
+  exportDictionary: function (instanceId: number, database: string) {
+    return request.get('/dictionary/instances/' + instanceId + '/export', {
+      params: { database: database },
+    });
+  },
+};

frontend/src/api/instanceDetail.ts

@@ -0,0 +1,52 @@
+import request from './request';
+
+export const instanceDetailApi = {
+  // Databases
+  listDatabases: (id: number) =>
+    request.get<any, string[]>('/instances/' + id + '/detail/databases'),
+
+  // Tables
+  listTables: (id: number, database: string) =>
+    request.get<any, any[]>('/instances/' + id + '/detail/tables', { params: { database: database } }),
+
+  // Table Detail
+  getTableDetail: (id: number, database: string, table: string) =>
+    request.get<any, any>('/instances/' + id + '/detail/table-detail', { params: { database: database, table: table } }),
+
+  // Users
+  listUsers: (id: number) =>
+    request.get<any, any[]>('/instances/' + id + '/detail/users'),
+
+  // Grants
+  getGrants: (id: number, user: string, host: string) =>
+    request.get<any, any>('/instances/' + id + '/detail/grants', { params: { user: user, host: host } }),
+
+  // Slow Queries
+  getSlowQueries: (id: number, database?: string) =>
+    request.get<any, any[]>('/instances/' + id + '/detail/slow-queries', { params: database ? { database: database } : {} }),
+
+  // Processlist
+  getProcesslist: (id: number) =>
+    request.get<any, any[]>('/instances/' + id + '/detail/processlist'),
+
+  // Kill Process
+  killProcess: (id: number, pid: number) =>
+    request.post<any, any>('/instances/' + id + '/detail/processlist/' + pid + '/kill'),
+
+  // Status
+  getStatus: (id: number) =>
+    request.get<any, any>('/instances/' + id + '/detail/status'),
+
+  // Variables
+  getVariables: (id: number) =>
+    request.get<any, any[]>('/instances/' + id + '/detail/variables'),
+};
+
+export const backupApi = {
+  list: (instanceId?: number) =>
+    request.get<any, any[]>('/backups', { params: instanceId ? { instance_id: instanceId } : {} }),
+  create: (data: any) =>
+    request.post<any, any>('/backups', data),
+  get: (id: number) =>
+    request.get<any, any>('/backups/' + id),
+};

frontend/src/api/redis.ts

@@ -0,0 +1,37 @@
+import request from './request';
+
+export var redisApi = {
+  getInfo: function (id: number) {
+    return request.get('/redis/' + id + '/info');
+  },
+  getDbsize: function (id: number, db: number) {
+    return request.get('/redis/' + id + '/dbsize', { params: { db: db } });
+  },
+  getKeys: function (id: number, params: Record<string, any>) {
+    return request.get('/redis/' + id + '/keys', { params: params });
+  },
+  getKeyDetail: function (id: number, key: string, db: number) {
+    return request.get('/redis/' + id + '/keys/' + encodeURIComponent(key), { params: { db: db } });
+  },
+  createKey: function (id: number, data: Record<string, any>) {
+    return request.post('/redis/' + id + '/keys', data);
+  },
+  deleteKey: function (id: number, key: string, db: number) {
+    return request.delete('/redis/' + id + '/keys/' + encodeURIComponent(key), { params: { db: db } });
+  },
+  setExpire: function (id: number, key: string, data: Record<string, any>) {
+    return request.put('/redis/' + id + '/keys/' + encodeURIComponent(key) + '/expire', data);
+  },
+  flushDb: function (id: number, db: number) {
+    return request.delete('/redis/' + id + '/flushdb', { params: { db: db } });
+  },
+  executeCommand: function (id: number, data: Record<string, any>) {
+    return request.post('/redis/' + id + '/command', data);
+  },
+  getSlowlog: function (id: number, count: number) {
+    return request.get('/redis/' + id + '/slowlog', { params: { count: count } });
+  },
+  getClients: function (id: number) {
+    return request.get('/redis/' + id + '/clients');
+  },
+};