feat: update error messages in NewApiAdapter tests to use correct Chinese translations

feat: enhance proxy usage parser to include cache read and creation tokens

feat: add billing details to ProxyLog interface and implement related formatting functions

fix: correct mojibake issues in source files and add regression test for mojibake detection

chore: add SQL migration for billing details in proxy_logs table

test: improve site speed button tests to ensure proper state updates without DOM lookups

docs/plans/2026-03-06-encoding-cleanup.md

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+# Source Encoding Cleanup Implementation Plan
+
+> **For Claude:** REQUIRED SUB-SKILL: Use superpowers:executing-plans to implement this plan task-by-task.
+
+**Goal:** Remove mojibake-corrupted Chinese literals from source and tests, then add regression coverage so the corruption does not re-enter the repository unnoticed.
+
+**Architecture:** Keep the fix narrow: add one regression test that scans `src/` for known mojibake markers, then replace each corrupted literal with the intended UTF-8 text in the affected source and test files. Verification stays focused on the new guard plus the currently failing Vitest files.
+
+**Tech Stack:** TypeScript, Vitest, Node.js filesystem APIs
+
+---
+
+### Task 1: Add a failing mojibake regression test
+
+**Files:**
+- Create: `src/encoding.mojibake.test.ts`
+- Test: `src/encoding.mojibake.test.ts`
+
+**Step 1: Write the failing test**
+
+Create a Vitest file that scans `src/**/*.{ts,tsx,js,jsx}` and fails when any source line contains known mojibake markers currently present in the repo.
+
+**Step 2: Run test to verify it fails**
+
+Run: `npm test -- src/encoding.mojibake.test.ts`
+Expected: FAIL with matches from the currently corrupted files.
+
+**Step 3: Keep the failure output readable**
+
+List file paths, line numbers, and the matched marker text in the assertion message.
+
+**Step 4: Re-run test to verify it still fails for the expected reason**
+
+Run: `npm test -- src/encoding.mojibake.test.ts`
+Expected: FAIL and only point at real mojibake matches.
+
+### Task 2: Repair corrupted source literals
+
+**Files:**
+- Modify: `src/server/routes/api/accounts.ts`
+- Modify: `src/web/i18n.supplement.ts`
+
+**Step 1: Replace the unsupported-platform mojibake message**
+
+Use a single readable Chinese message in `accounts.ts`, aligned with the existing translation key in `i18n.supplement.ts`.
+
+**Step 2: Remove or normalize the matching corrupted i18n entry**
+
+Keep only the valid UTF-8 translation key/value pair for that backend message.
+
+**Step 3: Run the mojibake test**
+
+Run: `npm test -- src/encoding.mojibake.test.ts`
+Expected: still FAIL, but no longer report the repaired source files.
+
+### Task 3: Repair corrupted test fixtures and selectors
+
+**Files:**
+- Modify: `src/web/pages/dashboard.site-speed-button.test.tsx`
+- Modify: `src/server/services/platforms/newApi.test.ts`
+
+**Step 1: Fix the dashboard selector text**
+
+Replace the corrupted speed-button label match with the intended UTF-8 text.
+
+**Step 2: Fix corrupted upstream fixture/expectation messages in `newApi.test.ts`**
+
+Use readable Chinese strings that match the adapter’s intended behavior.
+
+**Step 3: Run focused tests**
+
+Run: `npm test -- src/web/pages/dashboard.site-speed-button.test.tsx`
+Expected: PASS
+
+Run: `npm test -- src/server/services/platforms/newApi.test.ts`
+Expected: PASS
+
+### Task 4: Verify end-to-end cleanup
+
+**Files:**
+- Test: `src/encoding.mojibake.test.ts`
+- Test: `src/web/pages/accounts.rebind-panel-focus.test.tsx`
+- Test: `src/web/pages/dashboard.site-speed-button.test.tsx`
+- Test: `src/server/services/platforms/newApi.test.ts`
+
+**Step 1: Re-run the regression guard**
+
+Run: `npm test -- src/encoding.mojibake.test.ts`
+Expected: PASS
+
+**Step 2: Re-run the CI-facing tests**
+
+Run: `npm test -- src/web/pages/accounts.rebind-panel-focus.test.tsx src/web/pages/dashboard.site-speed-button.test.tsx`
+Expected: PASS
+
+**Step 3: Re-run the backend platform test**
+
+Run: `npm test -- src/server/services/platforms/newApi.test.ts`
+Expected: PASS