fix(deps): bump gomarkdown/markdown for GHSA-77fj-vx54-gvh7 (#9841)

Out-of-bounds read in SmartypantsRenderer.smartLeftAngle (CWE-125,
CVSS 7.5). Reachable transitively via LocalAGI's Email connector,
which renders inbound HTML email replies using html.CommonFlags
(includes Smartypants). An unmatched `<` in the inbound body could
panic the agent service.

Bump to v0.0.0-20260411013819-759bbc3e3207 (contains the fix). The
klauspost/compress entry loses its `// indirect` tag because
go mod tidy noticed pkg/utils/untar.go imports it directly.

Assisted-by: Claude:claude-opus-4-7 [Claude-Code]

Signed-off-by: Richard Palethorpe <io@richiejp.com>