feat(core) Smart approvals on (#10286)

## Summary
Turn on Smart Approvals by default

## Testing
 - [x] Updated unit tests

codex-rs/core/src/features.rs

@@ -464,12 +464,8 @@ pub const FEATURES: &[FeatureSpec] = &[
     FeatureSpec {
         id: Feature::RequestRule,
         key: "request_rule",
-        stage: Stage::Experimental {
-            name: "Smart approvals",
-            menu_description: "Get smarter \"Don't ask again\" rule requests.",
-            announcement: "NEW: Try Smart approvals to get smarter \"Don't ask again\" requests. Enable in /experimental!",
-        },
-        default_enabled: false,
+        stage: Stage::Stable,
+        default_enabled: true,
     },
     FeatureSpec {
         id: Feature::WindowsSandbox,

codex-rs/core/src/tools/spec.rs

@@ -1576,7 +1576,7 @@ mod tests {
         // Build expected from the same helpers used by the builder.
         let mut expected: BTreeMap<String, ToolSpec> = BTreeMap::from([]);
         for spec in [
-            create_exec_command_tool(false),
+            create_exec_command_tool(true),
             create_write_stdin_tool(),
             create_list_mcp_resources_tool(),
             create_list_mcp_resource_templates_tool(),
@@ -2410,7 +2410,7 @@ mod tests {
 
     #[test]
     fn test_shell_tool() {
-        let tool = super::create_shell_tool(false);
+        let tool = super::create_shell_tool(true);
         let ToolSpec::Function(ResponsesApiTool {
             description, name, ..
         }) = &tool
@@ -2440,7 +2440,7 @@ Examples of valid command strings:
 
     #[test]
     fn test_shell_command_tool() {
-        let tool = super::create_shell_command_tool(false);
+        let tool = super::create_shell_command_tool(true);
         let ToolSpec::Function(ResponsesApiTool {
             description, name, ..
         }) = &tool