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/api/chat_engine.go

@@ -21,6 +21,7 @@ type ChatEngine struct {
 	tools      json.RawMessage
 	onChunk    func(map[string]interface{})
 	stream    bool
+	TotalTokens int
 }
 
 // NewChatEngine creates a new ChatEngine instance.
@@ -71,6 +72,10 @@ func (ce *ChatEngine) RunWithTools(ctx context.Context, messages []orchestrator.
 			return finalContent, allToolCalls, allToolResults, err
 		}
 
+		if resp.Usage.TotalTokens > 0 {
+			ce.TotalTokens += resp.Usage.TotalTokens
+		}
+
 		choice := resp.Choices[0]
 		content := cleanThinkingTags(choice.Message.Content)
 
@@ -123,6 +128,11 @@ func (ce *ChatEngine) RunWithTools(ctx context.Context, messages []orchestrator.
 				"content":     result.Content,
 				"is_error":    result.IsError,
 			}
+			if result.Meta != nil {
+				for k, v := range result.Meta {
+					resultData[k] = v
+				}
+			}
 			allToolResults = append(allToolResults, map[string]interface{}{
 				"tool_call_id": tc.ID,
 				"name":        tc.Function.Name,
@@ -149,6 +159,11 @@ func (ce *ChatEngine) RunWithTools(ctx context.Context, messages []orchestrator.
 	return finalContent, allToolCalls, allToolResults, nil
 }
 
+// ProviderName returns the name of the active provider used by the engine.
+func (ce *ChatEngine) ProviderName() string {
+	return ce.orchestrator.ProviderName()
+}
+
 // RunNonStream executes chat without streaming content to client.
 func (ce *ChatEngine) RunNonStream(ctx context.Context, messages []orchestrator.Message) (string, error) {
 	var finalContent string
@@ -159,6 +174,10 @@ func (ce *ChatEngine) RunNonStream(ctx context.Context, messages []orchestrator.
 			return finalContent, err
 		}
 
+		if resp.Usage.TotalTokens > 0 {
+			ce.TotalTokens += resp.Usage.TotalTokens
+		}
+
 		choice := resp.Choices[0]
 		content := cleanThinkingTags(choice.Message.Content)