fix: encode parentheses in the deep link URLs

[a-essawy]

The Open in ChatGPT and Open in Cursor links rendered their entire URL-encoded prompt as visible text on the page.

Cause: encodeURIComponent does not escape parentheses, and the prompt contains "Rendobar (https://rendobar.com)". In markdown, the first raw ) inside text closes the link early, so everything after it rendered as body text. There were 47 raw parens in each URL.

Fix: percent-encode ( and ) as %28 and %29 when building the links. Both lines now contain exactly the two structural markdown parens, and the URLs round-trip: decoding the query back yields the canonical prompt byte for byte (3651 chars both ways). Cursor URL is 5101 chars, inside its 8000 cap.

Reported from the live page.