drop debug main() from keytab_default.dart

The file's only purpose is to expose the default-keytab string
constant, but it carried a `void main()` at the end that parsed
that constant and printed the result. That entry point:

- doesn't belong in `lib/` (Dart entry points live in `bin/` or
  `tool/`),
- pulls in `keytab_parse` and `keytab_token` imports that are
  unused everywhere else in the file,
- emits one of the pre-existing `avoid_print` analyze infos,
- only ever ran when a contributor manually invoked
  `dart lib/src/terminal/src/core/input/keytab/keytab_default.dart`,
  which the build never does.

Removing it unblocks the file from the coverage report (no
executable lines remain, just the string constant), drops the
unused imports, and shaves an analyze info off the pre-existing
total. If the dump-to-stdout helper turns out to be useful again,
the right home is a `tool/dump_keytab.dart` outside the package's
runtime surface.

Co-Authored-By: Claude <noreply@anthropic.com>

.pql/pql-plan.json

@@ -1,5 +1,5 @@
 {
-  "exported_at": "2026-05-06T21:37:05Z",
+  "exported_at": "2026-05-06T21:37:13Z",
   "decisions": [
     {
       "id": "D-1",

lib/src/terminal/src/core/input/keytab/keytab_default.dart

@@ -1,8 +1,5 @@
 // Based on xterm.dart v4.0.0 by xuty (MIT). See LICENSE in this directory.
 
-import 'package:clide/src/terminal/src/core/input/keytab/keytab_parse.dart';
-import 'package:clide/src/terminal/src/core/input/keytab/keytab_token.dart';
-
 const kDefaultKeytab = r'''
 # [README.default.Keytab] Default Keyboard Table
 #
@@ -207,9 +204,3 @@ key Down  +Shift-AppScreen  : scrollLineDown
 key PgDown  +Shift-AppScreen  : scrollPageDown
 key End   +Shift-AppScreen  : scrollDownToBottom
 ''';
-
-void main() {
-  final tokens = tokenize(kDefaultKeytab).toList();
-  final parser = KeytabParser()..addTokens(tokens);
-  print(parser.result);
-}