refactor: split unified-dashboard into usage-rows and codex-collector modules

Extract dashboard-usage-rows.ts (UsageRow, formatResetRemaining,
mergeClaudeDashboardAccounts, buildClaudeUsageRows, extractCodexUsageRows)
and codex-usage-collector.ts (fetchCodexUsage, applyCodexUsageToAccount,
buildCodexUsageRowsFromState, refresh functions returning data instead of
mutating module state). unified-dashboard.ts drops from 926 to 563 lines.

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

src/dashboard-usage-rows.test.ts

@@ -0,0 +1,207 @@
+import { describe, expect, it, vi } from 'vitest';
+
+import type { ClaudeAccountUsage } from './claude-usage.js';
+
+vi.mock('./claude-usage.js', () => ({
+  getClaudeProfile: (index: number) =>
+    index === 0
+      ? { email: 'a@example.com', planType: 'max' }
+      : { email: 'b@example.com', planType: 'pro' },
+}));
+
+import {
+  buildClaudeUsageRows,
+  extractCodexUsageRows,
+  mergeClaudeDashboardAccounts,
+} from './dashboard-usage-rows.js';
+import type { StatusSnapshot } from './status-dashboard.js';
+
+describe('extractCodexUsageRows staleness', () => {
+  const freshRows = [
+    { name: 'Codex1* pro', h5pct: 42, h5reset: '2h', d7pct: 65, d7reset: '3d' },
+  ];
+  const TEN_MIN = 600_000;
+
+  it('returns real rows when usageRowsFetchedAt is within maxAgeMs', () => {
+    const now = Date.now();
+    const snapshot: StatusSnapshot = {
+      agentType: 'codex',
+      assistantName: 'test',
+      updatedAt: new Date(now).toISOString(),
+      entries: [],
+      usageRows: freshRows,
+      usageRowsFetchedAt: new Date(now - TEN_MIN + 1000).toISOString(), // 9min59s ago
+    };
+
+    const result = extractCodexUsageRows(snapshot, TEN_MIN, now);
+    expect(result).toEqual(freshRows);
+  });
+
+  it('returns degraded row when usageRowsFetchedAt exceeds maxAgeMs', () => {
+    const now = Date.now();
+    const snapshot: StatusSnapshot = {
+      agentType: 'codex',
+      assistantName: 'test',
+      updatedAt: new Date(now).toISOString(), // heartbeat is fresh
+      entries: [],
+      usageRows: freshRows,
+      usageRowsFetchedAt: new Date(now - TEN_MIN - 1000).toISOString(), // 10min1s ago
+    };
+
+    const result = extractCodexUsageRows(snapshot, TEN_MIN, now);
+    expect(result).toEqual([
+      { name: 'Codex', h5pct: -1, h5reset: '', d7pct: -1, d7reset: '' },
+    ]);
+  });
+
+  it('returns degraded row when usageRowsFetchedAt is missing', () => {
+    const now = Date.now();
+    const snapshot: StatusSnapshot = {
+      agentType: 'codex',
+      assistantName: 'test',
+      updatedAt: new Date(now).toISOString(),
+      entries: [],
+      usageRows: freshRows,
+      // usageRowsFetchedAt intentionally omitted
+    };
+
+    const result = extractCodexUsageRows(snapshot, TEN_MIN, now);
+    expect(result).toEqual([
+      { name: 'Codex', h5pct: -1, h5reset: '', d7pct: -1, d7reset: '' },
+    ]);
+  });
+
+  it('returns empty array when snapshot is undefined', () => {
+    expect(extractCodexUsageRows(undefined, TEN_MIN)).toEqual([]);
+  });
+
+  it('returns empty array when usageRows is empty', () => {
+    const snapshot: StatusSnapshot = {
+      agentType: 'codex',
+      assistantName: 'test',
+      updatedAt: new Date().toISOString(),
+      entries: [],
+      usageRows: [],
+      usageRowsFetchedAt: new Date().toISOString(),
+    };
+    expect(extractCodexUsageRows(snapshot, TEN_MIN)).toEqual([]);
+  });
+});
+
+describe('dashboard Claude usage rows', () => {
+  it('keeps both Claude accounts visible when one account usage is unavailable', () => {
+    const rows = buildClaudeUsageRows([
+      {
+        index: 0,
+        masked: 'tok-a',
+        isActive: true,
+        isRateLimited: false,
+        usage: {
+          five_hour: {
+            utilization: 0.4,
+            resets_at: '2026-03-24T04:00:00+09:00',
+          },
+          seven_day: {
+            utilization: 0.7,
+            resets_at: '2026-03-29T04:00:00+09:00',
+          },
+        },
+      },
+      {
+        index: 1,
+        masked: 'tok-b',
+        isActive: false,
+        isRateLimited: true,
+        usage: null,
+      },
+    ]);
+
+    expect(rows).toHaveLength(2);
+    expect(rows[0]).toMatchObject({
+      name: 'Claude1* max',
+      h5pct: 40,
+      d7pct: 70,
+    });
+    expect(rows[1]).toMatchObject({
+      name: 'Claude2! pro',
+      h5pct: -1,
+      d7pct: -1,
+    });
+  });
+
+  it('preserves the last successful usage per account instead of collapsing to one cache entry', () => {
+    const cachedAccounts: ClaudeAccountUsage[] = [
+      {
+        index: 0,
+        masked: 'tok-a',
+        isActive: false,
+        isRateLimited: false,
+        usage: {
+          five_hour: {
+            utilization: 0.25,
+            resets_at: '2026-03-24T04:00:00+09:00',
+          },
+          seven_day: {
+            utilization: 0.5,
+            resets_at: '2026-03-29T04:00:00+09:00',
+          },
+        },
+      },
+      {
+        index: 1,
+        masked: 'tok-b',
+        isActive: true,
+        isRateLimited: false,
+        usage: {
+          five_hour: {
+            utilization: 0.6,
+            resets_at: '2026-03-24T06:00:00+09:00',
+          },
+          seven_day: {
+            utilization: 0.8,
+            resets_at: '2026-03-30T04:00:00+09:00',
+          },
+        },
+      },
+    ];
+    const liveAccounts: ClaudeAccountUsage[] = [
+      {
+        index: 0,
+        masked: 'tok-a',
+        isActive: true,
+        isRateLimited: false,
+        usage: null,
+      },
+      {
+        index: 1,
+        masked: 'tok-b',
+        isActive: false,
+        isRateLimited: true,
+        usage: {
+          five_hour: {
+            utilization: 0.9,
+            resets_at: '2026-03-24T08:00:00+09:00',
+          },
+          seven_day: {
+            utilization: 0.95,
+            resets_at: '2026-03-31T04:00:00+09:00',
+          },
+        },
+      },
+    ];
+
+    const merged = mergeClaudeDashboardAccounts(liveAccounts, cachedAccounts);
+
+    expect(merged).toHaveLength(2);
+    expect(merged[0]).toMatchObject({
+      index: 0,
+      isActive: true,
+      usage: cachedAccounts[0].usage,
+    });
+    expect(merged[1]).toMatchObject({
+      index: 1,
+      isRateLimited: true,
+      usage: liveAccounts[1].usage,
+    });
+  });
+});