Address PR review feedback

- Remove template-no-deprecated from recommended config snapshot
- Revert unrelated semicolon change in recommended-rules.js
- Delete docs/arg-deprecation-future-work.md (not part of this PR)
- Replace box-drawing characters in test comments with plain ASCII
- Revert rule-setup.js filter change (no .ts files in tests/lib/rules/)

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

Author: wagenet

docs/arg-deprecation-future-work.md

@@ -75,4 +75,4 @@ module.exports = {
   "ember/routes-segments-snake-case": "error",
   "ember/use-brace-expansion": "error",
   "ember/use-ember-data-rfc-395-imports": "error"
-};
+}

lib/recommended-rules.js

@@ -8,7 +8,6 @@ exports[`recommended rules > gjs config has the right list 1`] = `
 
 exports[`recommended rules > gts config has the right list 1`] = `
 [
-  "template-no-deprecated",
   "template-no-let-reference",
 ]
 `;

tests/__snapshots__/recommended.js.snap

@@ -6,7 +6,7 @@ const RuleTester = require('eslint').RuleTester;
 
 const FIXTURES_DIR = path.join(__dirname, '../rules-preprocessor/template-no-deprecated');
 
-// ─── Block 1: No TypeScript project — rule is a no-op ───────────────────────
+// Block 1: No TypeScript project -- rule is a no-op
 // When parserServices.program is absent, the rule returns {} and never reports.
 
 const ruleTester = new RuleTester({
@@ -37,7 +37,7 @@ ruleTester.run('template-no-deprecated', rule, {
   invalid: [],
 });
 
-// ─── Block 2: TypeScript project — full deprecation checking ─────────────────
+// Block 2: TypeScript project -- full deprecation checking
 
 const PREPROCESSOR_DIR = path.join(__dirname, '../rules-preprocessor');
 

tests/lib/rules/template-no-deprecated.js

@@ -32,9 +32,7 @@ describe('rules setup is correct', function () {
     const files = readdirSync(filePath);
 
     expect(RULE_NAMES).toEqual(
-      files
-        .filter((file) => !file.startsWith('.') && file.endsWith('.js'))
-        .map((file) => file.replace('.js', ''))
+      files.filter((file) => !file.startsWith('.')).map((file) => file.replace('.js', ''))
     );
   });