fix(home/kpi): format Current Coverage / Target with one decimal (#967)

* fix(home/kpi): format Current Coverage / Target with one decimal

When the backend returned a fractional `current_coverage` value, the
dashboard KPI tile rendered the raw float (e.g. `0.14648736342042862%`)
because the template literal `${data.current_coverage || 0}%` did no
formatting. Apply `.toFixed(1)` to both `current_coverage` and
`target_coverage` so the tile reads as e.g. `0.1%` / `80.0%`,
matching the convention already used in inventory.ts.

Regression test in dashboard.test.ts asserts the fractional input
renders as `0.1%` and never as the raw float.

* fix(api/test): repair Session.Role literal and gofmt drift

TestHandler_getPurchaseDetails_NotFound_IsClientError set a nonexistent
Session.Role field causing go vet to fail: the Session struct carries only
UserID/Email; admin is resolved via HasPermissionAPI. Drop the bogus field
and confer admin through mockAuth.grantAdmin() so the handler reaches the
GetExecutionByID not-found branch it asserts on.

Also split multi-statement-per-line entries in handler_purchases_guards_test.go
that caused gofmt to fail the pre-commit hook.

Author: cristim

frontend/src/__tests__/dashboard.test.ts

@@ -177,6 +177,26 @@ describe('Dashboard Module', () => {
       expect(summary?.innerHTML).toContain('YTD Savings');
     });
 
+    test('formats fractional current_coverage with one decimal (not raw float)', async () => {
+      (api.getDashboardSummary as jest.Mock).mockResolvedValue({
+        potential_monthly_savings: 0,
+        total_recommendations: 1,
+        active_commitments: 1,
+        committed_monthly: 100,
+        current_coverage: 0.14648736342042862,
+        target_coverage: 80,
+        ytd_savings: 0,
+        by_service: {}
+      });
+      (api.getUpcomingPurchases as jest.Mock).mockResolvedValue({ purchases: [] });
+
+      await loadDashboard();
+
+      const summary = document.getElementById('summary');
+      expect(summary?.innerHTML).toContain('0.1%');
+      expect(summary?.innerHTML).not.toContain('0.14648736342042862');
+    });
+
     test('renders the merged per-service savings chart', async () => {
       (api.getDashboardSummary as jest.Mock).mockResolvedValue({
         potential_monthly_savings: 1000,

frontend/src/dashboard.ts

@@ -268,8 +268,8 @@ function renderDashboardSummary(data: DashboardSummary, recs: readonly LocalReco
   // When no recommendations and no commitments exist, "100% coverage" is
   // misleading — nothing is being tracked. Show a dash instead.
   const nothingTracked = !data.total_recommendations && !data.active_commitments;
-  const coverageValue = nothingTracked ? '—' : `${data.current_coverage || 0}%`;
-  const coverageDetail = nothingTracked ? 'No services tracked' : `Target: ${data.target_coverage || 80}%`;
+  const coverageValue = nothingTracked ? '—' : `${(data.current_coverage || 0).toFixed(1)}%`;
+  const coverageDetail = nothingTracked ? 'No services tracked' : `Target: ${(data.target_coverage || 80).toFixed(1)}%`;
 
   // Render KPI tiles via DOM construction (textContent / appendChild)
   // rather than an innerHTML template literal, per the issue #340 plan's

internal/api/handler_purchases_test.go

@@ -1643,6 +1643,10 @@ func TestHandler_getPurchaseDetails_NotFound_IsClientError(t *testing.T) {
 		Email:  "admin@example.com",
 	}
 	mockAuth.On("ValidateSession", ctx, "admin-token").Return(adminSession, nil)
+	// getPurchaseDetails gates on requirePermission(view, purchases) before
+	// the GetExecutionByID lookup this test targets. Confer admin via the auth
+	// mock (the Session struct carries no role field; admin is resolved through
+	// HasPermissionAPI) so the handler reaches the not-found branch.
 	mockAuth.grantAdmin()
 
 	const missingID = "dddddddd-dddd-dddd-dddd-dddddddddddd"