feat(questions): make brand questions the primary monitoring & template axis

- add /questions/combination-fill endpoint with AI-driven, IP-region-aware matrix fill
- extract ip2region resolver from ops/app into shared/ipregion for cross-service use
- thread question_id filter through dashboard composite, citation summary, and collect-now
- switch template wizard from keyword inputs to brand-question selection (primary + supplemental)
- pass brand_question and supplemental_questions through assist/title/outline prompts
- add AiWaitingModal + 45s client timeout and request_timeout error mapping for long AI flows

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

server/internal/shared/config/config.go

@@ -28,6 +28,7 @@ type Config struct {
 	MonitoringDispatch MonitoringDispatchConfig `mapstructure:"monitoring_dispatch"`
 	Membership         MembershipConfig         `mapstructure:"membership"`
 	BrandLibrary       BrandLibraryConfig       `mapstructure:"brand_library"`
+	IPRegion           IPRegionConfig           `mapstructure:"ip_region"`
 	Redis              RedisConfig              `mapstructure:"redis"`
 	Qdrant             QdrantConfig             `mapstructure:"qdrant"`
 	ObjectStorage      ObjectStorageConfig      `mapstructure:"object_storage"`
@@ -244,6 +245,11 @@ type BrandLibraryConfig struct {
 	QuestionLimitsByPlan   map[string]int `mapstructure:"question_limits_by_plan"`
 }
 
+type IPRegionConfig struct {
+	V4XDBPath string `mapstructure:"v4_xdb_path"`
+	V6XDBPath string `mapstructure:"v6_xdb_path"`
+}
+
 func (c BrandLibraryConfig) BrandLimitForPlan(planCode string) int {
 	if strings.EqualFold(strings.TrimSpace(planCode), "free") {
 		return c.FreeBrandLimit
@@ -958,6 +964,12 @@ func applyEnvOverrides(cfg *Config) {
 	if trustedProxies, ok := lookupNonEmptyEnv("SERVER_TRUSTED_PROXIES"); ok {
 		cfg.Server.TrustedProxies = strings.Split(trustedProxies, ",")
 	}
+	if path, ok := lookupNonEmptyEnv("IP_REGION_V4_XDB_PATH"); ok {
+		cfg.IPRegion.V4XDBPath = path
+	}
+	if path, ok := lookupNonEmptyEnv("IP_REGION_V6_XDB_PATH"); ok {
+		cfg.IPRegion.V6XDBPath = path
+	}
 }
 
 func normalizeRabbitMQConfig(cfg *RabbitMQConfig) {

server/internal/shared/config/reload.go

@@ -65,6 +65,9 @@ func Diff(previous, current *Config) []FieldChange {
 	if !reflect.DeepEqual(previous.BrandLibrary, current.BrandLibrary) {
 		addChange("brand_library", true)
 	}
+	if previous.IPRegion != current.IPRegion {
+		addChange("ip_region", false)
+	}
 	if previous.Qdrant != current.Qdrant {
 		addChange("qdrant", true)
 	}