feat(FN-767): add Claude session reset time to usage modal

- Preserve Claude reset timestamps in the usage data model (usage.ts)
- Display session reset time in the UsageIndicator dashboard component
- Add component comments explaining reset-time rendering logic
- Add styles for the reset time display in the usage modal
- Add tests for usage data model and UsageIndicator component

packages/dashboard/src/usage.test.ts

@@ -734,6 +734,66 @@ describe("usage", () => {
       _resetSleepFn();
     });
 
+    it("populates resetAt timestamp for session window from API response", async () => {
+      const resetTime = new Date(Date.now() + 2 * 60 * 60 * 1000);
+      setupClaudeMocks({
+        credFileContent: {
+          accessToken: "test-token",
+          scopes: ["user:profile"],
+          subscriptionType: "pro",
+        },
+      });
+
+      setupClaudeApiResponse({
+        five_hour: {
+          utilization: 45.5,
+          resets_at: resetTime.toISOString(),
+        },
+        seven_day: {
+          utilization: 23.0,
+          resets_at: new Date(Date.now() + 5 * 24 * 60 * 60 * 1000).toISOString(),
+        },
+      });
+
+      const providers = await fetchAllProviderUsage();
+      const claude = providers.find((p) => p.name === "Claude")!;
+
+      expect(claude.status).toBe("ok");
+      expect(claude.windows).toHaveLength(2);
+
+      const sessionWindow = claude.windows.find((w) => w.label.includes("Session"))!;
+      expect(sessionWindow.resetAt).toBe(resetTime.toISOString());
+      expect(sessionWindow.resetText).toContain("resets in");
+
+      const weeklyWindow = claude.windows.find((w) => w.label === "Weekly")!;
+      expect(weeklyWindow.resetAt).toBeDefined();
+    });
+
+    it("omits resetAt when API response has no resets_at field", async () => {
+      setupClaudeMocks({
+        credFileContent: {
+          accessToken: "test-token",
+          scopes: ["user:profile"],
+          subscriptionType: "pro",
+        },
+      });
+
+      setupClaudeApiResponse({
+        five_hour: {
+          utilization: 30.0,
+          // no resets_at field
+        },
+      });
+
+      const providers = await fetchAllProviderUsage();
+      const claude = providers.find((p) => p.name === "Claude")!;
+
+      expect(claude.status).toBe("ok");
+      const sessionWindow = claude.windows.find((w) => w.label.includes("Session"))!;
+      expect(sessionWindow.resetAt).toBeUndefined();
+      expect(sessionWindow.resetText).toBeNull();
+    });
+
     it("handles empty JSON object from API gracefully", async () => {
       setupClaudeMocks({
         credFileContent: {

packages/dashboard/src/usage.ts

@@ -22,6 +22,7 @@ export interface UsageWindow {
   percentLeft: number; // 0-100
   resetText: string | null; // e.g., "resets in 2h"
   resetMs?: number; // ms until reset
+  resetAt?: string; // ISO 8601 timestamp of when the window resets (machine-readable)
   windowDurationMs?: number; // total window length
   pace?: UsagePace; // pace indicator for weekly windows
 }
@@ -651,6 +652,7 @@ async function fetchClaudeUsageViaCli(): Promise<ProviderUsage> {
           if (iso) {
             const msLeft = new Date(iso).getTime() - Date.now();
             window.resetMs = msLeft > 0 ? msLeft : 0;
+            window.resetAt = iso;
             if (!window.resetText) {
               window.resetText = msLeft > 0 ? `resets in ${formatDuration(msLeft)}` : "resetting now";
             }
@@ -833,9 +835,9 @@ async function fetchClaudeUsage(): Promise<ProviderUsage> {
       let resetText: string | null = null;
       let resetMs: number | undefined;
 
-      const resetAt = w.resets_at || w.reset_at || w.resetAt;
-      if (resetAt) {
-        const msLeft = new Date(resetAt).getTime() - Date.now();
+      const resetAtValue = w.resets_at || w.reset_at || w.resetAt;
+      if (resetAtValue) {
+        const msLeft = new Date(resetAtValue).getTime() - Date.now();
         resetMs = msLeft > 0 ? msLeft : 0;
         resetText = msLeft > 0 ? `resets in ${formatDuration(msLeft)}` : "resetting now";
       }
@@ -847,6 +849,7 @@ async function fetchClaudeUsage(): Promise<ProviderUsage> {
         resetText,
         windowDurationMs,
         resetMs,
+        resetAt: resetAtValue || undefined,
       };
     };