feat(model): keep the markdown structure in the card's changelog

[stanlyzoolo]

The [changelog] section of panel [2] destroyed the markdown it was handed. stripMarkdown trimmed a leading */- off every line, so list markers went; it left [text](url) raw, ignored fenced code, and its <...> strip swallowed <https://...> autolinks. wrapText then rebuilt lines from strings.Fields, losing every indent.

markdownToLines replaces it — one line pass with two state flags (inside a fence, inside an HTML comment) returning pre-wrapped lines tagged mdBody or mdHeading. Wrapping lives inside the converter because hanging indents need the block structure, and because styling must land on whole finished lines: wrapLine counts runes and knows nothing about ANSI. renderChangelogBlock is now just the consumer — headings take the new ui.ChangelogHeadingStyle (bold ColorText, one step above the muted body, no new color to compete with the peach section labels), everything else InfoStyle.

Before / after on keepkit's own v0.1.0 notes:

- Three-panel TUI: tracker list, tool          • Three-panel TUI: tracker list, tool
card (repo, stars, languages, notes),            card (repo, stars, languages, notes),
docs viewer (rendered README / --help)           docs viewer (rendered README / --help)
Install                                        Install                    <- bold
brew install stanlyzoolo/apps/keepkit            brew install stanlyzoolo/apps/keepkit

Rules worth naming

• CRLF is normalized first. GitHub bodies arrive CRLF from the web form, and a \r-suffixed closing fence would fail to match and swallow the rest of the body as code.
• Headings and list markers require the space after the marker, so #123 fixed ... stays an issue ref and **Breaking** stays a paragraph — the old Trim(line, "*_") bug class cannot come back.
• ---/***/___ collapse to a blank line, never a bullet: that is the separator above "Full Changelog".
• Inline order is load-bearing — images, links, autolinks, then the HTML strip that used to eat them.
• The underscore emphasis pattern requires a non-word rune outside both delimiters or update_cmd would lose its underscore, and it repeats until stable because a match consumes the boundaries it asserts (_a_ _b_ needs two passes).
• Two kinds only, no mdCode: everything that makes code special (verbatim, no inline processing, no wrap, a 2-space indent) lives in the converter, so a code tag would have no reader.

The empty-result fallback now also covers a non-empty body the converter consumed whole — a comment-only or separator-only release note lands on no release notes available. instead of a blank block.

Deliberately not glamour: the card stays muted and the render is synchronous inside Update().

Unchanged

The leading release-URL line, buildCard's clickable-line index and "a content line is a screen row" — TestBriefContentLineIsScreenRow, TestBuildCardLinks and TestMouseBriefLinkClick are untouched and green.

Test plan

• 62 new table rows across internal/model/textutil_test.go (new file) plus three renderChangelogBlock tests in render_test.go; TestStripMarkdown deleted with the function.
• markdownToLines, mdInline, mdEmitListItem, mdEmitWrapped, mdListLevel, mdCutComments and renderChangelogBlock are all at 100% of statements.
• Full CI matrix locally: go build / go vet ./... / go test -race ./... / golangci-lint run (0 issues), plus the cross-compile step.
• Eyeballed against keepkit's live v0.1.0 release notes at briefW 58 and 30.

Known limitation, unchanged from the code this replaces

The HTML-tag strip cuts any <...> outside a fenced block, so --tool <name> in prose or `Vec<String>` in an inline code span loses it. A "looks like a real tag" pattern does not help — <name> is the shape of an HTML tag. Protecting inline code spans from the strip is the natural follow-up.

🤖 Generated with Claude Code