feat(cost-guard): global Gemini daily budget + EOC alarm; trial requires verified email

packages/ai-contracts/src/gemini.ts

@@ -109,11 +109,17 @@ export interface BudgetStore {
   getDailySpendUsd(): Promise<number>;
   /** Increment daily spend by amountUsd; return new total. */
   incrementDailySpendUsd(amountUsd: number): Promise<number>;
+  /**
+   * Optional: called when the daily budget is exceeded. Implementations can
+   * raise an alert (e.g. write to Redis / DB) so ops-summary/EOC can surface it.
+   */
+  raiseBudgetAlarm?(): Promise<void>;
 }
 
 /** In-memory budget store for tests / single-process dev. */
 export class MemoryBudgetStore implements BudgetStore {
   private spend = 0;
+  private alarmRaised = false;
   async getDailySpendUsd(): Promise<number> {
     return this.spend;
   }
@@ -121,8 +127,15 @@ export class MemoryBudgetStore implements BudgetStore {
     this.spend += amountUsd;
     return this.spend;
   }
+  async raiseBudgetAlarm(): Promise<void> {
+    this.alarmRaised = true;
+  }
+  alarmWasRaised(): boolean {
+    return this.alarmRaised;
+  }
   reset() {
     this.spend = 0;
+    this.alarmRaised = false;
   }
 }
 
@@ -920,7 +933,11 @@ Språk: ${lang}.`;
   private async isOverBudget(estimateUsd: number): Promise<boolean> {
     if (this.cfg.dailyBudgetUsd <= 0 || !this.cfg.budgetStore) return false;
     const current = await this.cfg.budgetStore.getDailySpendUsd();
-    return current + estimateUsd > this.cfg.dailyBudgetUsd;
+    const over = current + estimateUsd > this.cfg.dailyBudgetUsd;
+    if (over && this.cfg.budgetStore.raiseBudgetAlarm) {
+      await this.cfg.budgetStore.raiseBudgetAlarm();
+    }
+    return over;
   }
 
   private async recordSpend(costUsd: number): Promise<void> {