fix(render): scope strict lint to composition

[miguel-heygen]

What

Scope pre-render lint to the file selected by render --composition.

Why

On CLI 0.7.53, render --composition standalone.html --strict still linted sibling root HTML files, emitted multiple_root_compositions, and aborted. Users had to copy the same entry and assets into an isolated temporary project even though the command explicitly selected one composition.

How

• Allow lintProject to accept an explicit entry file.
• Treat that file as the root lint source and resolve its local assets relative to its location.
• Skip unrelated compositions/ discovery and the project-wide multiple-root rule only for explicit-entry lint.
• Pass the resolved entry from the render command when --composition is set.
• Preserve existing whole-project behavior when rendering index.html.

Test plan

• Reproduced published 0.7.53 strict abort with two valid root compositions
• bunx vitest run packages/cli/src/utils/lintProject.test.ts packages/cli/src/commands/render.test.ts (125 passed)
• bun run --filter @hyperframes/cli typecheck
• npx oxfmt --check packages/lint/src/project.ts packages/cli/src/commands/render.ts packages/cli/src/utils/lintProject.test.ts
• npx oxlint packages/lint/src/project.ts packages/cli/src/commands/render.ts packages/cli/src/utils/lintProject.test.ts