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>

internal/config/config.go

@@ -289,7 +289,7 @@ func Default() *MuyueConfig {
 		},
 		{
 			Name:    "mimo",
-			Model:   "MiMo-V2.5-Pro",
+			Model:   "mimo-v2.5-pro",
 			BaseURL: "https://token-plan-ams.xiaomimimo.com/v1",
 			Active:  false,
 		},