fix(website-to-video): correct local render dimensions guidance

[miguel-heygen]

What

• replace the unsupported local render --width/--height example with a draft-quality render
• explain that local canvas dimensions come from composition metadata
• add a content regression test for the documented local render command

Why

CLI feedback reported that v0.7.52 rejected the documented --width/--height flags. Those flags belong to cloud rendering; local hyperframes render does not expose them.

How

The validation fallback now uses --quality draft at the composition's authored dimensions. A focused test extracts the local render example and prevents cloud-only dimension flags from returning.

Test plan

• bun run --cwd packages/cli test src/commands/websiteToVideoSkillContent.test.ts
• pre-commit lint, format, skills-manifest, fallow, and typecheck hooks