Replace Precise footer loaders with SaaS Maker StudioFooter

[sarthakagrawal927]

Moves the SPA footer (Layout) and the generated public curriculum/system-design/articles pages from the hosted Precise loaders (ai-chat-footer.js, project-strip.js, newsletter-capture.js, feedback-launcher.js) to the framework-free StudioFooter from @saas-maker/ui v0.1.15 (<studio-footer>; renderStudioFooterHtml for generated pages).

• Variant studio, poster wordmark, existing footer art, catalog id swe-interview-prep, newsletter capture; existing link groups kept.
• New dependency: @saas-maker/ui (github tag v0.1.15), used by the page generator; footer.css/footer.js vendored in public/.
• Removed the floating SaaSMakerFeedback launcher (feedback is in the footer) and its test; replaced the Precise timing test.
• Generated page CSS now sits in a lowest cascade layer so it cannot override footer styles.
• Library gap: footer email input collapses on mobile (flex-1 in a column); patched locally with min-height.
• Checked: tsc, biome, vitest (987), knip, size; screenshots at 390/768/1440, no horizontal scroll, no footer console errors.

Codex was not used for this one; drafted directly.

🤖 Generated with Claude Code