chore(release): v0.7.21

[argszero]

Summary

Release PR for v0.7.21 — version bump only. All the feature work already landed on main through the six UI redesign PRs (#152 → #157); this PR bumps the crate version, the front-end cache-bust string and the changelog so the release can be tagged.

• Cargo.toml / Cargo.lock: 0.7.20 → 0.7.21
• ui/index.html: asset cache-bust ?v=20260911-2 → ?v=20260911-3 (5 references: style.css, api.js, data.js, i18n.js, app.js)
• CHANGELOG.md: new v0.7.21 (2026-09-11) entry summarising the full-site UI redesign

Related Issue

Rant 2026-09-11T21:03:06 (project aitokenpool) — "发布 v0.7.21（宿主授权：2026-09-11 21:02 '发布新版本'）". No GitHub issue.

Changes

• Version bump Cargo.toml + Cargo.lock (0.7.20 → 0.7.21)
• Front-end cache-bust ?v=20260911-2 → ?v=20260911-3
• CHANGELOG.md v0.7.21 entry
• No configuration or data-structure changes (pure front-end release; backend contract unchanged, deployment layout unchanged — DB stays on NAS, WAL still disabled)

What v0.7.21 ships (already merged on main)

Six independently deployable front-end slices, all already squashed into main:

1. #152 bafd223 — migrate design tokens to the OKLCH system + add the prototype baseline
2. #153 e33bf2e — redesign the login page as a two-column layout + rework the sidebar
3. #154 75dcb2c — shared component layer (stat-card / pill / tag / trend / bar-list / toolbar / search / empty) + define the previously missing button variants
4. #155 7e094e0 — dashboard, model market and sharing views
5. #156 41bb6d1 — wallet and transactions views
6. #157 09e4121 — settings, admin and ops views

Preserved throughout: ZH/EN i18n (762 × 2 exact key-set parity), transactions column-filter row (focus retention + IME guard), 24h + custom time range, real server-side pagination, tokenBrk wrapping, CSV export, withdraw/gift types. Backend additions: /api/ops/runtime now also returns today_hours (0–23 zero-filled) and key_health.

Tests

• cargo test — 148 passed, 0 failed
• cargo fmt --check — clean
• cargo clippy — clean, no warnings
• node --check ×4 (app.js / api.js / data.js / i18n.js) — all clean
• i18n ZH/EN exact key-set parity — 762 = 762, 0 missing, 0 unresolved data-i18n
• No new tests needed (version/metadata-only change)

Checklist

• Branch name follows the project convention (release/v0.7.21, matching the release/v0.7.20 precedent)
• Commit message uses Conventional Commits (chore(release): v0.7.21)
• Single responsibility, minimal diff (4 files, metadata only)

Release steps after merge

1. Tag v0.7.21 on the squashed main tip (verify git rev-parse v0.7.21^{} == git rev-parse main before pushing)
2. Wait for Docker Publish (GHCR v0.7.21 + latest) to succeed
3. Bump the deploy repo (gitlab.xinluex.com/shaoaq/aitokenpool, ci/docker-compose.yml) image v0.7.20 → v0.7.21, push, watch the GitLab pipeline
4. Verify healthz reports 0.7.21 on atp-dev.shenbiai.net and check the redesigned UI in the browser