Address PR feedback: explicit lifetime and dialect delegation

- Use explicit lifetime on register() for public API clarity, with
  clippy allow attribute for elidable_lifetime_names
- Delegate with_vscode_dialect() to with_vscode_vocabulary() instead
  of with_vscode_keywords() to match the semantic intent chain

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Author: SteveL-MSFT

lib/dsc-lib-jsonschema/src/vscode/keywords/vscode_keyword.rs

@@ -131,7 +131,8 @@ impl VSCodeKeyword {
     /// [`VSCodeValidationOptionsExtensions`]: crate::vscode::VSCodeValidationOptionsExtensions
     /// [`with_vscode_keyword()`]: crate::vscode::VSCodeValidationOptionsExtensions::with_vscode_keyword
     /// [`VSCODE_DIALECT_REGISTRY`]: crate::vscode::VSCODE_DIALECT_REGISTRY
-    pub fn register(self, options: ValidationOptions<'_>) -> ValidationOptions<'_> {
+    #[allow(clippy::elidable_lifetime_names)]
+    pub fn register<'i>(self, options: ValidationOptions<'i>) -> ValidationOptions<'i> {
         match self {
             Self::AllowComments => options.with_keyword(
                 AllowCommentsKeyword::KEYWORD_NAME,

lib/dsc-lib-jsonschema/src/vscode/validation_options_extensions.rs

@@ -261,6 +261,6 @@ impl<'i> VSCodeValidationOptionsExtensions<'i> for ValidationOptions<'i> {
         self.with_vscode_keywords()
     }
     fn with_vscode_dialect(self) -> ValidationOptions<'i> {
-        self.with_vscode_keywords()
+        self.with_vscode_vocabulary()
     }
 }