Remove unused callListMethod function (#2657)

Removes the unused `callListMethod` generic helper from
`internal/mcp/connection.go`. This function was never called anywhere in
the codebase and was flagged by `golangci-lint`.

The similar `callParamMethod` helper IS used and remains untouched.

Author: lpcox

guards/github-guard/rust-guard/src/labels/constants.rs

@@ -5,6 +5,7 @@
 /// Common label string constants to ensure consistency across the codebase
 pub mod label_constants {
     pub const NONE: &str = "none";
+    #[cfg(test)]
     pub const SECRET: &str = "secret";
     pub const PRIVATE_USER: &str = "private:user";
     pub const READER_PREFIX: &str = "unapproved:";

guards/github-guard/rust-guard/src/labels/helpers.rs

@@ -326,6 +326,7 @@ pub fn ensure_integrity_baseline(
 // ============================================================================
 
 /// Returns a vec with the "secret" label
+#[cfg(test)]
 #[inline]
 pub fn secret_label() -> Vec<String> {
     vec![label_constants::SECRET.to_string()]

guards/github-guard/rust-guard/src/labels/mod.rs

@@ -49,11 +49,13 @@ pub use helpers::{
     has_author_association, is_blocked_user, is_bot, is_graphql_wrapper, is_mcp_text_wrapper,
     is_search_result_wrapper, issue_integrity, limit_items_with_log, make_item_path,
     merged_integrity, none_integrity, pr_integrity, private_scope_label, private_user_label,
-    project_github_label, reader_integrity, search_result_total_count, secret_label,
+    project_github_label, reader_integrity, search_result_total_count,
     writer_integrity, MinIntegrity, PolicyContext, PolicyScopeEntry, ScopeKind,
 };
 #[cfg(test)]
 pub use helpers::has_approval_label;
+#[cfg(test)]
+pub use helpers::secret_label;
 
 // Re-export response labeling functions (wrappers that pass PolicyContext)
 pub fn apply_tool_labels(

internal/mcp/connection.go

@@ -502,19 +502,6 @@ func unmarshalParams(params interface{}, target interface{}) error {
 	return nil
 }
 
-// callListMethod is a generic helper for SDK list operations with no additional parameters.
-// It handles the common pattern of: requireSession → SDK call → marshalToResponse.
-func (c *Connection) callListMethod(call func() (interface{}, error)) (*Response, error) {
-	if err := c.requireSession(); err != nil {
-		return nil, err
-	}
-	result, err := call()
-	if err != nil {
-		return nil, err
-	}
-	return marshalToResponse(result)
-}
-
 // callParamMethod is a generic helper for SDK operations that require typed parameters.
 // It handles the common pattern of: requireSession → unmarshalParams → fn(params) → marshalToResponse.
 // P is the type of the parameter struct to unmarshal into.