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/tenant/app/question_combination_fill_test.go

@@ -0,0 +1,32 @@
+package app
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestQuestionCombinationRegionTermsFromIPRegion(t *testing.T) {
+	got := questionCombinationRegionTermsFromIPRegion("中国|0|安徽省|合肥市|电信")
+	want := []string{"合肥", "华东"}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("region terms = %#v, want %#v", got, want)
+	}
+}
+
+func TestBuildQuestionCombinationFillFallback(t *testing.T) {
+	description := "GEO 与 AI 搜索优化平台"
+	got := buildQuestionCombinationFillFallback(&questionBrandContext{
+		BrandName:   "GeoRankly",
+		Description: &description,
+	}, []string{"上海", "华东"}, QuestionCombinationFillRequest{})
+
+	if !reflect.DeepEqual(got.Region, []string{"上海", "华东"}) {
+		t.Fatalf("region = %#v", got.Region)
+	}
+	if len(got.Core) < 3 || got.Core[0] != "GEO" {
+		t.Fatalf("core fallback = %#v", got.Core)
+	}
+	if len(got.Prefix) != 4 || len(got.Industry) != 4 || len(got.Suffix) != 4 {
+		t.Fatalf("expected four hot terms for non-region columns, got %#v", got)
+	}
+}