feat(ui): URL hash routing — share/bookmark/refresh restore (v1.19 A)

[argszero]

Summary

UI/UE 4th-round deepening — item A: URL hash routing (rant 2026-08-17T20:39:30, v1.19).

Views now sync with the address-bar hash (#/marketplace, #/wallet, …), enabling bookmark / share / refresh-restore / back-forward navigation with zero external dependencies:

• switchView syncs location.hash via history.pushState (skip when already equal → no duplicate entries; pushState never fires hashchange → no loop)
• Back/forward (hashchange listener) follows the view
• Illegal hash (#/xxx not in the 7 views) → falls back to dashboard without rewriting the URL (avoids polluting history / double-back)
• Empty hash → no-op (default behavior preserved)
• Refresh then login → restores the view from the pre-refresh hash (pendingHashView); guest-mode / not-logged-in states unaffected
• Guest-restricted hash (e.g. #/settings) → intercepted by GUEST_VIEWS (toast), view + URL untouched, no new history entry

Docs: docs/user-stories.md v1.19 + ui/README.md「URL hash 路由约定」section. Verified by node --check, DOM-stub smoke test (13 assertions: refresh restore / pushState / back+forward / illegal hash / guest interception), cargo test, cargo fmt --check.

Rant (verbatim)

Rant: UI/UE 第四轮多角度深化 — 状态保持、信息密度、原生控件美化、帮助可达性（宿主 2026-08-17 第四轮指示：继续从多角度美化 UI、优化 UE）

A. URL hash 路由 — 刷新/前进后退保持视图

• 视图切换时同步 location.hash（如 #/marketplace），刷新后恢复上次视图；支持浏览器前进/后退（hashchange 事件）
• 游客模式登录页、未登录状态不冲突；hash 非法时回仪表盘

Related

• Rant timestamp: 2026-08-17T20:39:30.507364 (project aitokenpool, status in_progress)
• Branch: feat/ui-ue-round4-hash-routing (per rant: 分支 feat/ui-ue-round4; items B–G to follow in subsequent PRs)

Tests

• node --check ui/js/app.js
• DOM-stub smoke test — 13/13 assertions pass
• cargo test — 1 passed
• cargo fmt --check