Update test cases to verify the fix and improve documentation

Co-authored-by: RyanCavanaugh <6685088+RyanCavanaugh@users.noreply.github.com>

Author: Copilot

tests/cases/fourslash/completionsSymbolAutoimportFromTypeOnlyImport.ts

@@ -1,5 +1,9 @@
 /// <reference path="fourslash.ts" />
 
+// Test for issue #61894: Symbol auto-import bug with existing type-only imports
+// Verifies that symbols used in element access expressions are imported as values,
+// not added to existing type-only imports, when completing inside thing[...]
+
 // @noLib: true
 
 // @Filename: /globals.d.ts
@@ -32,7 +36,7 @@ verify.completions({
     },
 });
 
-// This should demonstrate the bug - the symbol should be imported as a value, not as a type
+// Verify the fix - the symbol should be imported as a value, not as a type
 verify.applyCodeActionFromCompletion("", {
     name: "SYM_FOO_BAR",
     source: "/exportsSymbol",

tests/cases/fourslash/completionsSymbolAutoimportFromTypeOnlyImportControl.ts

@@ -1,5 +1,8 @@
 /// <reference path="fourslash.ts" />
 
+// Control test for issue #61894: Symbol auto-import without existing type-only imports
+// Verifies that symbols are correctly imported as values when there are no existing imports
+
 // @noLib: true
 
 // @Filename: /globals.d.ts