Bare URLs wrapped in `[url](url)` self-links on sync

Affected: Plane Cloud, official GitHub integration. See also: meta-issue on destructive overwrite (issue 01).

Symptom

Bare URLs in a GitHub issue or comment body are wrapped in redundant [url](url) markdown links after a sync round-trip.

Impact

• GitHub auto-linkifies bare URLs natively. Wrapping them in explicit [url](url) is redundant.
• More importantly, the wrapping breaks for URLs containing characters that need escaping in markdown link syntax (parens, brackets). The original bare-URL form rendered correctly; the wrapped form may render broken.
• Body bytes grow unnecessarily on every round-trip.

Ask

Preserve bare URLs as bare URLs. Don't wrap them in self-referential [url](url) links.

Reproduction

1. Connect a GitHub repo to a Plane workspace via the official GitHub integration. Set sync to bidirectional.
2. Create a GitHub issue whose body contains a bare URL with special characters in the path (parens or brackets). Apply the Plane label.
3. To exercise the destructive Plane→GH push, follow the trigger recipe in meta-issue 01.

Start with the official GitHub integration's bidirectional sync path and reproduce the documented round-trip using a bare URL with parentheses or brackets. Compare the GitHub input, Plane-stored HTML, and pushed Markdown; done means bare URLs remain unwrapped and still render correctly after sync.