Post-merge-review: Fix template-no-at-ember-render-modifiers: detect GJS/GTS imports

[johanrd]

What's broken on master

The rule matches a hardcoded kebab-case list (did-insert, did-update, will-destroy). That works for classic .hbs where the resolver exposes modifiers by their canonical name, but it misses the GJS/GTS usage entirely:

import didInsert from '@ember/render-modifiers/modifiers/did-insert';

<template>
  <div {{didInsert this.setup}}></div>
</template>

Here the local name is user-chosen (could be didInsert, onInsert, myInsert, anything). The rule has no way to match the user's identifier against the render-modifier import.

Fix

In .gjs/.gts files, track ImportDeclaration nodes whose source is one of @ember/render-modifiers/modifiers/did-insert / did-update / will-destroy, recording the default-import local name → canonical kebab name. Flag modifier usages whose identifier matches a tracked local name. In .hbs, keep the kebab-case matching (matches upstream ember-template-lint exactly — upstream is HBS-only).

Pattern is the same as template-no-builtin-form-components, which already tracks @ember/component imports in strict mode.

Test plan

• 30/30 tests pass on the branch
• 4 new invalid GJS tests covering didInsert / didUpdate / willDestroy imports (and a renamed myInsert) fail on master — master silently ignores them all
• 2 new valid GJS tests confirm that (a) a bare kebab-looking identifier without an import is not flagged, and (b) an unrelated local import named didInsert from a non-render-modifiers path is not flagged
• Existing HBS tests unchanged (the kebab-case HBS path is preserved)

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Co-written by Claude.