[Repo Assist] fix: Markdown.ToMd preserves DirectLink and DirectImage titles

[github-actions]

🤖 This is an automated PR from Repo Assist.

Root Cause

Markdown.ToMd serialised DirectLink and DirectImage spans by grouping them in an F# OR-pattern that used a wildcard for the title field:

// Before
| IndirectLink(body, _, LookupKey ctx.Links (link, _), _)
| DirectLink(body, link, _, _)          // ← title discarded
| IndirectLink(body, link, _, _) -> "[" + formatSpans ctx body + "](" + link + ")"

| DirectImage(body, link, _, _) -> sprintf "![%s](%s)" body link   // ← title discarded

A Markdown fragment such as [text](url "My Title") would round-trip as [text](url), silently losing the title attribute.

Fix

Give DirectLink and DirectImage their own match branches so the optional title can be emitted in CommonMark form ("title"):

// After
| DirectLink(body, link, title, _) ->
    let t = title |> Option.map (fun t -> sprintf " \"%s\"" (t.Replace("\"", "\\\""))) |> Option.defaultValue ""
    "[" + formatSpans ctx body + "](" + link + t + ")"

| DirectImage(body, link, title, _) ->
    let t = title |> Option.map (fun t -> sprintf " \"%s\"" (t.Replace("\"", "\\\""))) |> Option.defaultValue ""
    sprintf "![%s](%s)" body (link + t)

The title value is escaped to handle embedded double-quote characters per CommonMark spec.

Changes

File	Change
src/FSharp.Formatting.Markdown/MarkdownUtils.fs	Separate DirectLink/DirectImage from OR-pattern; emit title when present
tests/FSharp.Markdown.Tests/Markdown.fs	Three new round-trip tests: link-with-title, link-without-title (regression), image-with-title
RELEASE_NOTES.md	Changelog entry under [Unreleased] / Fixed

Test Status

• ✅ dotnet build FSharp.Formatting.sln --configuration Release — 0 warnings, 0 errors
• ✅ dotnet test tests/FSharp.Markdown.Tests --configuration Release --no-build — 284/284 passed (includes 3 new tests)
• ✅ dotnet fantomas … --check — formatting verified

Generated by Repo Assist · ◷

To install this agentic workflow, run

gh aw add githubnext/agentics/workflows/repo-assist.md

Generated by 🌈 Repo Assist, see workflow run. Learn more.

To install this agentic workflow, run

gh aw add githubnext/agentics/workflows/repo-assist.md@e1ecf341a90b7bc2021e77c58685d7e269e20b99