fix(ui): dynamic user nickname in sidebar chip + settings form (rant 2026-08-22T00:01:52)

[argszero]

Summary

Fix hardcoded nickname 「阿零」 in the frontend per host rant 2026-08-22T00:01:52 (project=aitokenpool). The sidebar chip and the settings nickname input showed a static "阿零" instead of the real user name — and saving the settings form without editing would overwrite the real nickname with "阿零".

• Sidebar chip (ui/index.html): the user chip now has ids (#side-name / #side-avatar); the static <strong>阿零</strong> / avatar 零 are gone
• renderUserChip() (ui/js/app.js): fills the sidebar name with D.USER.name (fallback: email prefix) and the avatar with the name's first character; called from enterApp() on login and session restore
• Settings nickname input (ui/index.html + renderSettings()): the input gets id settings-nickname, an empty default, and is filled with the real name when the settings view renders — saving can no longer clobber the real nickname
• Test seed (src/db.rs): the #[cfg(test)] demo user's name '阿零' → 'demo' (no hardcoded nickname left in source)

Related Issue

Host rant 2026-08-22T00:01:52.266430+08:00 (project=aitokenpool), verbatim:

前端昵称「阿零」硬编码：左下角用户名 + 设置页昵称框都不显示真实用户昵称

建议修复

1. 左下角用户芯片改为动态：<strong id="side-name">，登录成功后 $("#side-name").textContent = D.USER.name（取不到时 fallback 邮箱前缀）；头像「零」改为 name 首字符
2. 设置页昵称输入框加载时填充真实 D.USER.name（替换静态 value="阿零"）
3. 清理 db.rs 残留的 demo 账号死代码（'阿零' 插入 demo@aitokenpool.local）
4. 检查是否还有其他静态「阿零」硬编码

Changes

• Sidebar chip dynamic: #side-name = D.USER.name (fallback email prefix), avatar = name first char
• Settings nickname input filled with real name on render (no static 阿零)
• db.rs test seed name neutralized
• No other static 阿零 remaining (source values; comments reference the rant only)

Tests

• cargo test — 136/136 passed
• cargo fmt --check — clean
• cargo clippy --all-targets -- -D warnings — clean
• node --check ui/js/app.js — clean

Checklist

• Branch name follows convention (fix/user-chip-nickname)
• Commit message uses Conventional Commits
• Single responsibility, minimal change