feat: terminal sudo blocking, token tracking, mermaid & consumption UI

- Block sudo/doas commands when not running as root
- Add real token counting from API responses
- Track and display consumption by provider/day
- Add Mermaid diagram rendering in Shell and Studio
- Add copy-to-clipboard buttons for code blocks
- Support tables in AI message rendering
- Update system prompt with context (date, time, root status)

💘 Generated with Crush

Assisted-by: MiniMax-M2.7 via Crush <crush@charm.land>

web/src/components/App.jsx

@@ -94,10 +94,8 @@ export default function App() {
     shell: [
       { keys: `${layout.keys.ctrl}+${layout.keys.shift}+C`, desc: t('statusbar.copy') },
       { keys: `${layout.keys.ctrl}+${layout.keys.shift}+V`, desc: t('statusbar.paste') },
-      { keys: `${layout.keys.ctrl}+F`, desc: t('statusbar.search') },
-      { keys: `${layout.keys.ctrl}+/Ctrl−`, desc: t('statusbar.zoom') },
-      { keys: `Alt+1-7`, desc: t('statusbar.switchTab') },
-      { keys: `${layout.keys.shift}+Tab`, desc: t('statusbar.nextTab') },
+      { keys: `${layout.keys.ctrl}+${layout.keys.shift}+F`, desc: t('statusbar.search') },
+      { keys: `${layout.keys.ctrl}++/${layout.keys.ctrl}+−`, desc: t('statusbar.zoom') },
       { keys: layout.keys.enter, desc: t('statusbar.runCommand') },
       { keys: `${layout.keys.up}/${layout.keys.down}`, desc: t('statusbar.commandHistory') },
     ],