Fix AI insight prompt passing raw cents instead of dollar amounts

recentExpenses and chart were JSON-stringified with raw amountCents/
expensesCents/paychecksCents values, causing the model to read e.g.
10000 as $10,000 instead of $100. Both arrays are now mapped through
centsToDisplay() before inclusion in the prompt, matching the pattern
already used for totals and category breakdown.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/lib/insights.ts

@@ -112,8 +112,8 @@ function buildInsightPrompt(snapshot: Awaited<ReturnType<typeof getDashboardSnap
       ? `Pay schedule: biweekly, ${centsToDisplay(snapshot.paySchedule.amountCents)} per paycheck, projected pay dates this month: ${snapshot.paySchedule.projectedDates.join(", ") || "none"}`
       : null,
     `Category breakdown: ${JSON.stringify(categoryBreakdown)}`,
-    `Recent expenses: ${JSON.stringify(snapshot.recentExpenses)}`,
-    `Daily chart points: ${JSON.stringify(snapshot.chart)}`,
+    `Recent expenses: ${JSON.stringify(snapshot.recentExpenses.map((e) => ({ title: e.title, amount: centsToDisplay(e.amountCents), date: e.date, category: getCategoryLabel(e.category as CategoryValue) })))}`,
+    `Daily chart points: ${JSON.stringify(snapshot.chart.map((p) => ({ date: p.date, expenses: centsToDisplay(p.expensesCents), paychecks: centsToDisplay(p.paychecksCents) })))}`,
     "Do not mention missing data unless it materially affects the advice.",
   ]
     .filter(Boolean)