feat(logs): unify filtering across list and stats

Make runtime log queries support request correlation and date-range diagnostics with shared filtering semantics so the log page can use one consistent contract.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/api/log.ts

@@ -6,12 +6,18 @@ export interface Log {
   level: 'debug' | 'info' | 'warning' | 'error'
   type: 'agent' | 'system' | 'chat'
   user_id: string | null
+  request_id: string | null
+  route: string | null
+  method: string | null
+  status_code: number | null
+  error_type: string | null
+  operation: string | null
   message: string
   source: string | null
-  details: string | null
-  duration_ms: string | null
-  created_at: string
-  updated_at: string
+  details: Record<string, unknown> | null
+  duration_ms: number | null
+  created_at: string | null
+  updated_at: string | null
 }
 
 export interface LogStats {
@@ -36,19 +42,27 @@ export interface LogQueryResult {
   page_size: number
 }
 
+export interface LogQueryParams {
+  log_type?: string
+  level?: string
+  source?: string
+  request_id?: string
+  route?: string
+  operation?: string
+  status_code?: number
+  start_at?: string
+  end_at?: string
+  page?: number
+  page_size?: number
+}
+
 export const logApi = {
-  list: (params?: {
-    log_type?: string
-    level?: string
-    source?: string
-    page?: number
-    page_size?: number
-  }): Promise<AxiosResponse<LogQueryResult>> => {
+  list: (params?: LogQueryParams): Promise<AxiosResponse<LogQueryResult>> => {
     return api.get('/api/logs', { params })
   },
 
-  getStats: (hours?: number): Promise<AxiosResponse<LogStats>> => {
-    return api.get('/api/logs/stats', { params: { hours } })
+  getStats: (params?: LogQueryParams): Promise<AxiosResponse<LogStats>> => {
+    return api.get('/api/logs/stats', { params })
   },
 
   getRecent: (params?: {