feat(server): hot-reload config store and reloadable infra clients

- Replace single Load() with a watching Store that re-reads config files
  (and config.local.yaml) and fans out a ReloadEvent with a per-field diff
  so consumers can decide whether the change is hot-applicable or requires
  a process restart.
- Wrap llm, retrieval, vector store, and object storage clients in
  Reloadable* shells so the bootstrap can swap their underlying impls when
  config changes without re-instantiating handlers.
- Make jwt.Manager and ops TokenIssuer mutable under a lock so secrets and
  TTLs can be rotated live; thread default plan code through a setter on
  the ops AdminUserService.
- Wire ConfigStore through bootstrap and every cmd/main.go, scheduler /
  worker / tenant-api / ops-api start the watcher; services and handlers
  take a config.Provider so they always read current values for things
  like generation.stream_enabled, scheduler dispatch, retrieval, etc.
- Switch shared/config decoding off viper to a Kratos-derived runtime
  package so env placeholders (\${VAR:default}) resolve consistently and
  the same source machinery powers both the loader and the watcher.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

server/internal/tenant/app/kol_assist_generate_context.go

@@ -19,10 +19,10 @@ const kolAssistReferenceContentMaxRunes = 6000
 var kolAssistURLPattern = regexp.MustCompile(`https?://[^\s]+`)
 
 type kolAssistURLResolver struct {
-	arkBaseURL string
-	arkAPIKey  string
-	httpClient *http.Client
-	logger     *zap.Logger
+	cfg            config.LLMConfig
+	configProvider runtimeConfigProvider
+	httpClient     *http.Client
+	logger         *zap.Logger
 }
 
 type kolAssistReferenceMaterial struct {
@@ -38,17 +38,25 @@ func newKolAssistURLResolver(llmCfg config.LLMConfig, logger *zap.Logger) *kolAs
 	}
 
 	return &kolAssistURLResolver{
-		arkBaseURL: strings.TrimRight(baseURL, "/"),
-		arkAPIKey:  strings.TrimSpace(llmCfg.APIKey),
+		cfg: config.LLMConfig{
+			BaseURL: baseURL,
+			APIKey:  strings.TrimSpace(llmCfg.APIKey),
+		},
 		httpClient: &http.Client{Timeout: defaultKnowledgeURLParseTimeout},
 		logger:     logger,
 	}
 }
 
 func (r *kolAssistURLResolver) extract(ctx context.Context, rawURL string) (*kolAssistReferenceMaterial, error) {
-	if r == nil || r.httpClient == nil || strings.TrimSpace(r.arkAPIKey) == "" {
+	llmCfg := r.runtimeConfig()
+	apiKey := strings.TrimSpace(llmCfg.APIKey)
+	if r == nil || r.httpClient == nil || apiKey == "" {
 		return nil, fmt.Errorf("url resolver is unavailable")
 	}
+	baseURL := strings.TrimRight(strings.TrimSpace(llmCfg.BaseURL), "/")
+	if baseURL == "" {
+		baseURL = defaultKnowledgeArkBaseURL
+	}
 
 	body, err := json.Marshal(arkToolExecuteRequest{
 		ActionName: "LinkReader",
@@ -62,11 +70,11 @@ func (r *kolAssistURLResolver) extract(ctx context.Context, rawURL string) (*kol
 		return nil, fmt.Errorf("marshal webpage parser request: %w", err)
 	}
 
-	req, err := http.NewRequestWithContext(ctx, http.MethodPost, r.arkBaseURL+"/tools/execute", bytes.NewReader(body))
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, baseURL+"/tools/execute", bytes.NewReader(body))
 	if err != nil {
 		return nil, fmt.Errorf("create webpage parser request: %w", err)
 	}
-	req.Header.Set("Authorization", "Bearer "+r.arkAPIKey)
+	req.Header.Set("Authorization", "Bearer "+apiKey)
 	req.Header.Set("Content-Type", "application/json")
 
 	resp, err := r.httpClient.Do(req)
@@ -108,6 +116,26 @@ func (r *kolAssistURLResolver) extract(ctx context.Context, rawURL string) (*kol
 	}, nil
 }
 
+func (r *kolAssistURLResolver) withConfigProvider(provider runtimeConfigProvider) *kolAssistURLResolver {
+	if r == nil {
+		return nil
+	}
+	r.configProvider = provider
+	return r
+}
+
+func (r *kolAssistURLResolver) runtimeConfig() config.LLMConfig {
+	if r != nil && r.configProvider != nil {
+		if cfg := r.configProvider.Current(); cfg != nil {
+			return cfg.LLM
+		}
+	}
+	if r == nil {
+		return config.LLMConfig{BaseURL: defaultKnowledgeArkBaseURL}
+	}
+	return r.cfg
+}
+
 func (s *KolAssistService) enrichGenerateDescription(ctx context.Context, description string) string {
 	description = strings.TrimSpace(description)
 	urls := extractKolAssistURLs(description)