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/template_prompt.go

@@ -67,7 +67,9 @@ func buildGenerationKnowledgeQuery(params map[string]interface{}) string {
 	appendValue(stringValue(params["product_name"]))
 	appendValue(stringValue(params["subject"]))
 	appendValue(stringValue(params["brand_name"]))
+	appendValue(stringValue(params["brand_question"]))
 	appendValue(stringValue(params["primary_keyword"]))
+	appendValue(formatPromptValue(params["supplemental_questions"]))
 	appendValue(stringValue(params["key_points"]))
 	appendValue(stringValue(params["review_intro_hook"]))
 
@@ -187,7 +189,10 @@ func buildPromptContext(params map[string]interface{}) string {
 		"product_name",
 		"subject",
 		"brand_name",
+		"brand_question",
+		"primary_question",
 		"primary_keyword",
+		"supplemental_questions",
 		"brand",
 		"category",
 		"count",