Add system memory monitoring, Bedrock support, and Discord integrations

- Add CPU/GPU memory monitoring endpoint and frontend widget
- Add Amazon Bedrock model support (API key / inference profiles) plus model selector entries
- Add Discord weather/laundry notification job (JMA forecast + LLM-generated message)
- Add Discord bot that replies to mentions via the configured LLM, with weather-aware context
- Add scheduled "useless tips" job with separate webhook and quiet-hours skip
- Switch FastAPI startup to lifespan handler, log viewer, markdown rendering, and toast UI additions

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

frontend/src/api/client.ts

@@ -1,3 +1,14 @@
+export interface ApiLog {
+  id: number
+  session_id: string | null
+  model: string
+  request_json: string
+  response_text: string | null
+  error: string | null
+  latency_ms: number | null
+  created_at: string
+}
+
 export interface SessionInfo {
   id: string
   title: string
@@ -6,22 +17,64 @@ export interface SessionInfo {
 }
 
 export interface SSEChunk {
-  type: 'session_id' | 'chunk' | 'done'
+  type: 'session_id' | 'chunk' | 'done' | 'error'
   value?: string
 }
 
 const BASE = ''
 
+async function parseJson<T>(res: Response, label: string): Promise<T> {
+  const ct = res.headers.get('content-type') ?? ''
+  if (!ct.includes('application/json')) {
+    throw new Error(`${label}: バックエンドに接続できません (${res.status} ${res.statusText})`)
+  }
+  if (!res.ok) {
+    const body = await res.json().catch(() => ({}))
+    throw new Error(`${label}: ${body.detail ?? res.statusText}`)
+  }
+  return res.json()
+}
+
 export async function fetchSessions(): Promise<SessionInfo[]> {
   const res = await fetch(`${BASE}/chat/sessions`)
-  if (!res.ok) throw new Error('Failed to fetch sessions')
-  return res.json()
+  return parseJson<SessionInfo[]>(res, 'セッション取得')
+}
+
+export interface MessageRecord {
+  id: number
+  role: 'user' | 'assistant' | 'system'
+  content: string
+  created_at: string
+}
+
+export async function fetchMessages(sessionId: string): Promise<MessageRecord[]> {
+  const res = await fetch(`${BASE}/chat/sessions/${sessionId}/messages`)
+  return parseJson<MessageRecord[]>(res, 'メッセージ取得')
 }
 
 export async function deleteSession(sessionId: string): Promise<void> {
   await fetch(`${BASE}/chat/sessions/${sessionId}`, { method: 'DELETE' })
 }
 
+export async function fetchLogs(params: {
+  session_id?: string
+  status?: 'ok' | 'error'
+  limit?: number
+  offset?: number
+} = {}): Promise<ApiLog[]> {
+  const q = new URLSearchParams()
+  if (params.session_id) q.set('session_id', params.session_id)
+  if (params.status) q.set('status', params.status)
+  if (params.limit != null) q.set('limit', String(params.limit))
+  if (params.offset != null) q.set('offset', String(params.offset))
+  const res = await fetch(`${BASE}/logs?${q}`)
+  return parseJson<ApiLog[]>(res, 'ログ取得')
+}
+
+export async function deleteLog(logId: number): Promise<void> {
+  await fetch(`${BASE}/logs/${logId}`, { method: 'DELETE' })
+}
+
 export function streamChat(
   message: string,
   sessionId: string | null,
@@ -54,8 +107,8 @@ export function streamChat(
             try {
               const parsed: SSEChunk = JSON.parse(line.slice(6))
               onChunk(parsed)
-            } catch {
-              // ignore malformed
+            } catch (e) {
+              console.error('[SSE] JSON parse error:', e, '| raw:', line)
             }
           }
         }