Use linear matcher for string template literals

[tim-smart]

Summary

• use a linear left-to-right matcher when every template literal span is exactly StringKeyword
• retain the existing regex fallback for all other span types
• add regex-equivalence coverage, an adversarial performance guard, and an effect patch changeset

Scope

• Union spans containing StringKeyword remain on the existing regex path and are not optimized here.
• getTemplateLiteralCapturingRegExp is untouched. TemplateLiteralParser still uses that capturing regex and may exhibit the same backtracking behavior.

Validation

• pnpm lint-fix
• pnpm test run packages/effect/test/Schema/Schema/TemplateLiteral/TemplateLiteral.test.ts
• pnpm check
• pnpm build
• pnpm docgen

Closes EFF-209

[pullfrog]

• Checkout PR Use linear matcher for string template literals #6761 and read the diff
• Triage: understand what the PR does and its domain
• Specialist decision: identify unresolved questions
• Dispatch specialists if needed
• Aggregate findings & draft review
• Submit review via pullfrog_create_pull_request_review

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[changeset-bot]

🦋 Changeset detected

Latest commit: dce60f0

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

This PR includes changesets to release 1 package

Name	Type
effect	Patch

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