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/ai_point_usage.go

@@ -24,6 +24,7 @@ const (
 	AIUsageTypeKolPromptGenerate        = "kol_prompt_generate"
 	AIUsageTypeKolPromptOptimize        = "kol_prompt_optimize"
 	AIUsageTypeQuestionDistill          = "question_distill"
+	AIUsageTypeQuestionCombinationFill  = "question_combination_fill"
 
 	aiPointsQuotaType = "ai_points"
 )