Fix getTagDefForTagName seen tag tracking

[DylanPiercey]

The seen set in getTagDefForTagName was checked by tag definition but populated with tag name, so the guard never hit: the watch file check re-ran on every call and duplicate watch file entries piled up. Fixing the mismatch improves a 400-template compileSync benchmark from ~222ms to ~188ms (median).

[changeset-bot]

🦋 Changeset detected

Latest commit: 1bc31db

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@marko/compiler	Patch

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Reviewing files that changed from the base of the PR and between 74b41ab and 1bc31db.

📒 Files selected for processing (2)

• .changeset/tagdef-seen.md
• packages/compiler/src/babel-utils/taglib.js

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Walkthrough

getTagDefForTagName now tracks seen tag definitions by tagDef object identity instead of tag name. This prevents repeated watch-file checks and duplicate watch-file entries when multiple tag names resolve to the same definition. A patch changeset documents the compiler fix.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly describes the fix to seen-tag tracking in getTagDefForTagName.
Description check	✅ Passed	The description accurately explains the seen-set mismatch, its effects, and the benchmark improvement.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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