feat: add ENABLE_CLAUDEAI_MCP_SERVERS opt-out setting

Adds a toggle in the MCP Servers settings section to control whether
Claude Code connects to MCP servers configured in Claude.ai. When
disabled, sets ENABLE_CLAUDEAI_MCP_SERVERS=false. Also fixes a
pre-existing omission of disable_cron from the TypeScript HikariConfig
interface.

Closes #210

src-tauri/src/config.rs

@@ -40,6 +40,9 @@ pub struct ClaudeStartOptions {
 
     #[serde(default = "default_include_git_instructions")]
     pub include_git_instructions: bool,
+
+    #[serde(default = "default_enable_claudeai_mcp_servers")]
+    pub enable_claudeai_mcp_servers: bool,
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
@@ -180,6 +183,9 @@ pub struct HikariConfig {
 
     #[serde(default = "default_include_git_instructions")]
     pub include_git_instructions: bool,
+
+    #[serde(default = "default_enable_claudeai_mcp_servers")]
+    pub enable_claudeai_mcp_servers: bool,
 }
 
 impl Default for HikariConfig {
@@ -228,6 +234,7 @@ impl Default for HikariConfig {
             task_loop_include_summary: false,
             disable_cron: false,
             include_git_instructions: true,
+            enable_claudeai_mcp_servers: true,
         }
     }
 }
@@ -276,6 +283,10 @@ fn default_include_git_instructions() -> bool {
     true
 }
 
+fn default_enable_claudeai_mcp_servers() -> bool {
+    true
+}
+
 #[derive(Debug, Clone, Serialize, Deserialize, Default, PartialEq)]
 #[serde(rename_all = "lowercase")]
 pub enum BudgetAction {
@@ -372,6 +383,7 @@ mod tests {
         assert!(!config.task_loop_include_summary);
         assert!(!config.disable_cron);
         assert!(config.include_git_instructions);
+        assert!(config.enable_claudeai_mcp_servers);
     }
 
     #[test]
@@ -420,6 +432,7 @@ mod tests {
             task_loop_include_summary: true,
             disable_cron: true,
             include_git_instructions: false,
+            enable_claudeai_mcp_servers: false,
         };
 
         let json = serde_json::to_string(&config).unwrap();
@@ -439,6 +452,7 @@ mod tests {
         assert!(deserialized.task_loop_include_summary);
         assert!(deserialized.disable_cron);
         assert!(!deserialized.include_git_instructions);
+        assert!(!deserialized.enable_claudeai_mcp_servers);
     }
 
     #[test]

src-tauri/src/wsl_bridge.rs

@@ -320,6 +320,11 @@ impl WslBridge {
                 cmd.env("CLAUDE_CODE_DISABLE_GIT_INSTRUCTIONS", "1");
             }
 
+            // Opt out of claude.ai MCP servers if requested
+            if !options.enable_claudeai_mcp_servers {
+                cmd.env("ENABLE_CLAUDEAI_MCP_SERVERS", "false");
+            }
+
             cmd
         } else {
             // Running on Windows - use wsl with bash login shell to ensure PATH is loaded
@@ -382,6 +387,11 @@ impl WslBridge {
                 claude_cmd.push_str("CLAUDE_CODE_DISABLE_GIT_INSTRUCTIONS=1 ");
             }
 
+            // Opt out of claude.ai MCP servers if requested
+            if !options.enable_claudeai_mcp_servers {
+                claude_cmd.push_str("ENABLE_CLAUDEAI_MCP_SERVERS=false ");
+            }
+
             claude_cmd.push_str(
                 "claude --output-format stream-json --input-format stream-json --verbose",
             );