fix(translator): sanitize tool names for Gemini function_declarations compatibility

Claude Code and MCP clients may send tool names containing characters
invalid for Gemini's function_declarations (e.g. '/', '@', spaces).
Sanitize on request via SanitizeFunctionName and restore original names
on response for both antigravity/claude and gemini-cli/claude translators.

internal/translator/gemini-cli/claude/gemini-cli_claude_response.go

@@ -28,6 +28,9 @@ type Params struct {
 	ResponseType     int  // Current response type: 0=none, 1=content, 2=thinking, 3=function
 	ResponseIndex    int  // Index counter for content blocks in the streaming response
 	HasContent       bool // Tracks whether any content (text, thinking, or tool use) has been output
+
+	// Reverse map: sanitized Gemini function name → original Claude tool name.
+	ToolNameMap map[string]string
 }
 
 // toolUseIDCounter provides a process-wide unique counter for tool use identifiers.
@@ -55,6 +58,7 @@ func ConvertGeminiCLIResponseToClaude(_ context.Context, _ string, originalReque
 			HasFirstResponse: false,
 			ResponseType:     0,
 			ResponseIndex:    0,
+			ToolNameMap:      util.SanitizedToolNameMap(originalRequestRawJSON),
 		}
 	}
 
@@ -165,7 +169,7 @@ func ConvertGeminiCLIResponseToClaude(_ context.Context, _ string, originalReque
 				// Handle function/tool calls from the AI model
 				// This processes tool usage requests and formats them for Claude Code API compatibility
 				usedTool = true
-				fcName := functionCallResult.Get("name").String()
+				fcName := util.RestoreSanitizedToolName((*param).(*Params).ToolNameMap, functionCallResult.Get("name").String())
 
 				// Handle state transitions when switching to function calls
 				// Close any existing function call block first
@@ -248,7 +252,7 @@ func ConvertGeminiCLIResponseToClaude(_ context.Context, _ string, originalReque
 // Returns:
 //   - []byte: A Claude-compatible JSON response.
 func ConvertGeminiCLIResponseToClaudeNonStream(_ context.Context, _ string, originalRequestRawJSON, requestRawJSON, rawJSON []byte, _ *any) []byte {
-	_ = originalRequestRawJSON
+	toolNameMap := util.SanitizedToolNameMap(originalRequestRawJSON)
 	_ = requestRawJSON
 
 	root := gjson.ParseBytes(rawJSON)
@@ -306,7 +310,7 @@ func ConvertGeminiCLIResponseToClaudeNonStream(_ context.Context, _ string, orig
 				flushText()
 				hasToolCall = true
 
-				name := functionCall.Get("name").String()
+				name := util.RestoreSanitizedToolName(toolNameMap, functionCall.Get("name").String())
 				toolIDCounter++
 				toolBlock := []byte(`{"type":"tool_use","id":"","name":"","input":{}}`)
 				toolBlock, _ = sjson.SetBytes(toolBlock, "id", fmt.Sprintf("tool_%d", toolIDCounter))