fix(card): adapt to profile magnitude — abbreviate ticks, truncate long text (#9)

The stress test caught real overflows from profiles the author doesn't
have:

- Y-axis tick labels were raw integers. A user with 10,000+ yearly
  contributions or 1000+ monthly commits would render "10000" / "1000000"
  at text-anchor="end" against a ~28 px gutter — the digits spilled
  leftward past x=0. formatTick now abbreviates: 999→"999", 1500→"1.5k",
  12345→"12k", 1234567→"1.2M". No label exceeds 4 chars, all fit the
  gutter for every card that uses niceTicks.

- Profile details dumped Company / Location / Website / title verbatim,
  which works for the author (VNG, Ho Chi Minh, miti99.com) but not for
  40-char strings. Each row truncates at 40 runes; the title truncates at
  34. Uses a rune-aware truncate() helper hoisted out of top-starred-repos
  into svg.go so every list-style card can share it.

- Streak date range collapses to a single-year form ("Jan 2 — Dec 31")
  when start.Year() == end.Year() and to "YYYY — YYYY" across years. The
  previous "Jan 2 — Dec 31, 2025" format at 10 px × 21 chars pushed past
  the ~113 px column width.

The TestCardsFitFrame stress test was reading text-anchor and font-size
with a non-greedy regex that missed attributes whose position varied. It
now parses the opening <text> tag as a block and extracts each attribute
with its own regex, so text-anchor="end" / "middle" elements are no
longer false negatives. The check also estimates rendered width
(0.6 × font-size × len) and asserts the implied left/right edges stay in
the frame — catching exactly the class of bug the axis-tick case
represents.

internal/card/axis.go

@@ -1,6 +1,7 @@
 package card
 
 import (
+	"fmt"
 	"math"
 	"strconv"
 )
@@ -36,7 +37,42 @@ func niceTicks(max float64, targetTicks int) []float64 {
 	return out
 }
 
-// formatTick renders a float tick label. Integer-valued ticks drop decimals.
+// formatTick renders a float tick label, abbreviating thousands / millions /
+// billions so every possible y-axis label fits within ≤4 characters. The
+// leftPad gutter of every chart card is sized for ≤4 chars at 10 px font,
+// so anything wider would overflow past the card frame for busy profiles
+// (1000+ monthly commits, 10k+ yearly contributions, etc).
+//
+// Examples:
+//
+//	999       -> "999"
+//	1_000     -> "1k"
+//	1_500     -> "1.5k"
+//	12_345    -> "12k"
+//	1_234_567 -> "1.2M"
 func formatTick(v float64) string {
-	return strconv.FormatFloat(v, 'f', -1, 64)
+	if v == 0 {
+		return "0"
+	}
+	abs := math.Abs(v)
+	if abs < 1000 {
+		return strconv.FormatFloat(v, 'f', -1, 64)
+	}
+	var div float64
+	var suffix string
+	switch {
+	case abs < 1_000_000:
+		div, suffix = 1000, "k"
+	case abs < 1_000_000_000:
+		div, suffix = 1_000_000, "M"
+	default:
+		div, suffix = 1_000_000_000, "B"
+	}
+	n := v / div
+	// One decimal place only when it matters. 1.5k stays "1.5k", 10k stays
+	// "10k" not "10.0k", 500k stays "500k".
+	if math.Abs(n) >= 10 || n == math.Trunc(n) {
+		return strconv.FormatFloat(n, 'f', 0, 64) + suffix
+	}
+	return fmt.Sprintf("%.1f%s", n, suffix)
 }

internal/card/card_test.go

@@ -199,6 +199,14 @@ func TestCardsFitFrame(t *testing.T) {
 // be fragile against the Catmull-Rom Bezier output.
 var attrCoord = regexp.MustCompile(`(?:x|y|x1|y1|x2|y2|cx|cy)="(-?\d+(?:\.\d+)?)"`)
 
+// textBlock captures the opening <text …> tag attributes and the inner text.
+// We parse individual attributes with separate regexes so attribute order
+// doesn't matter.
+var textBlock = regexp.MustCompile(`<text\s+([^>]*)>([^<]*)</text>`)
+var attrX = regexp.MustCompile(`\bx="(-?\d+(?:\.\d+)?)"`)
+var attrAnchor = regexp.MustCompile(`\btext-anchor="([^"]+)"`)
+var attrFontSize = regexp.MustCompile(`\bfont-size="(\d+)"`)
+
 func assertInFrame(t *testing.T, name, svg string) {
 	t.Helper()
 	const (
@@ -210,7 +218,6 @@ func assertInFrame(t *testing.T, name, svg string) {
 		if err != nil {
 			continue
 		}
-		// Distinguish x-ish vs y-ish by the first attr char.
 		isX := strings.HasPrefix(m[0], "x") || strings.HasPrefix(m[0], "cx")
 		limit := float64(maxY)
 		if isX {
@@ -220,6 +227,60 @@ func assertInFrame(t *testing.T, name, svg string) {
 			t.Errorf("%s: attribute %q value %v outside frame (limit %v)", name, m[0], v, limit)
 		}
 	}
+
+	// <text> elements: the x attribute is the anchor point, but the string
+	// actually extends outward from it. Right-anchored axis labels are the
+	// classic overflow trap — the attr x stays inside the frame while the
+	// rendered digits spill past x=0. Estimate width conservatively
+	// (0.6 × font-size per char; Segoe UI avg is ~0.55).
+	for _, m := range textBlock.FindAllStringSubmatch(svg, -1) {
+		attrs := m[1]
+		text := m[2]
+
+		xm := attrX.FindStringSubmatch(attrs)
+		if xm == nil {
+			continue
+		}
+		x, err := strconv.ParseFloat(xm[1], 64)
+		if err != nil {
+			continue
+		}
+		anchor := ""
+		if am := attrAnchor.FindStringSubmatch(attrs); am != nil {
+			anchor = am[1]
+		}
+		fontSize := 12.0
+		if fm := attrFontSize.FindStringSubmatch(attrs); fm != nil {
+			if f, err := strconv.ParseFloat(fm[1], 64); err == nil {
+				fontSize = f
+			}
+		}
+
+		width := float64(runeLen(text)) * fontSize * 0.6
+		var left, right float64
+		switch anchor {
+		case "end":
+			left, right = x-width, x
+		case "middle":
+			left, right = x-width/2, x+width/2
+		default:
+			left, right = x, x+width
+		}
+		if left < -2 {
+			t.Errorf("%s: <text>%q at x=%v anchor=%q extends to left=%.1f (outside frame)", name, text, x, anchor, left)
+		}
+		if right > maxX+2 {
+			t.Errorf("%s: <text>%q at x=%v anchor=%q extends to right=%.1f (outside frame)", name, text, x, anchor, right)
+		}
+	}
+}
+
+func runeLen(s string) int {
+	n := 0
+	for range s {
+		n++
+	}
+	return n
 }
 
 // adversarialProfile exercises every card against the worst-case inputs a

internal/card/profile.go

@@ -41,6 +41,11 @@ func (profileCard) SVG(p *github.Profile, t theme.Theme) ([]byte, error) {
 	// scale factor to fit 16x16 octicon into iconSize box
 	scale := float64(iconSize) / 16.0
 
+	// Row text starts at rowX+iconSize+8 = 40; the right edge safety margin
+	// is width-10 = 330. Space = 290 px; at 12 px font × 0.6 char width =
+	// 7.2 px/char, so ~40 characters fit. Clamping here means a 200-char
+	// company name can't push the frame open.
+	const rowMaxChars = 40
 	for i, r := range rows {
 		y := rowY0 + i*rowDY
 		// icon glyph: translate to row position, scale down, fill with muted.
@@ -48,7 +53,7 @@ func (profileCard) SVG(p *github.Profile, t theme.Theme) ([]byte, error) {
   <g transform="translate(%d,%.2f) scale(%.3f)" fill="%s">%s</g>
   <text x="%d" y="%d" font-size="12" fill="%s">%s</text>`,
 			rowX, float64(y-iconSize+2), scale, t.Muted, r.icon,
-			rowX+iconSize+8, y, t.Text, escapeXML(r.value))
+			rowX+iconSize+8, y, t.Text, escapeXML(truncate(r.value, rowMaxChars)))
 	}
 
 	b.WriteString(footer)
@@ -56,12 +61,15 @@ func (profileCard) SVG(p *github.Profile, t theme.Theme) ([]byte, error) {
 }
 
 // cardTitle mirrors github-profile-summary-cards: "login (Name)" when name is
-// set, "login" otherwise.
+// set, "login" otherwise. Clamped to 34 runes — the title renders at 15 px
+// weight 600, so ~35 chars is the max that reliably fits in 340−20−10=310
+// px of title row.
 func cardTitle(p *github.Profile) string {
+	raw := p.Login
 	if p.Name != "" {
-		return p.Login + " (" + p.Name + ")"
+		raw = p.Login + " (" + p.Name + ")"
 	}
-	return p.Login
+	return truncate(raw, 34)
 }
 
 func buildProfileRows(p *github.Profile) []profileRow {

internal/card/streak.go

@@ -126,18 +126,22 @@ func activeDaysDetail(active, total int) string {
 	return fmt.Sprintf("of %s total (%d%%)", formatInt(total), pct)
 }
 
-// streakRange formats the open/close dates of a streak as "Mon 2 — Wed 11"
-// when both are present. Returns "" when the streak is zero-length so the
-// card renders cleanly.
+// streakRange formats the open/close dates of a streak for the small detail
+// line. Each column is ~113 px wide at font-size 10 (≤ ~18 chars), so we
+// aggressively drop year and redundant parts when they'd blow the budget.
+//
+//	same day     -> "Jan 2 2025"
+//	same year    -> "Jan 2 — Dec 31"
+//	different    -> "2024 — 2026"
 func streakRange(start, end time.Time) string {
 	if start.IsZero() || end.IsZero() {
 		return ""
 	}
 	if start.Equal(end) {
-		return start.Format("Jan 2, 2006")
+		return start.Format("Jan 2 2006")
 	}
-	if start.Year() == end.Year() {
-		return start.Format("Jan 2") + " — " + end.Format("Jan 2, 2006")
+	if start.Year() != end.Year() {
+		return fmt.Sprintf("%d — %d", start.Year(), end.Year())
 	}
-	return start.Format("Jan 2006") + " — " + end.Format("Jan 2006")
+	return start.Format("Jan 2") + " — " + end.Format("Jan 2")
 }

internal/card/svg.go

@@ -18,6 +18,19 @@ func escapeXML(s string) string {
 	return r.Replace(s)
 }
 
+// truncate returns s clamped to at most n runes, appending "…" when the
+// input was longer. Operates on runes so multi-byte strings (emoji, CJK)
+// don't split mid-codepoint. Used by every row-style card to make sure a
+// pathological name / company / location can't push the card's right edge
+// out past the 340 px frame.
+func truncate(s string, n int) string {
+	r := []rune(s)
+	if len(r) <= n {
+		return s
+	}
+	return strings.TrimRight(string(r[:n-1]), ".") + "…"
+}
+
 // formatInt renders n with thousands separators (e.g. 12345 → "12,345").
 func formatInt(n int) string {
 	neg := n < 0

internal/card/top_starred_repos.go

@@ -59,7 +59,7 @@ func (topStarredReposCard) SVG(p *github.Profile, t theme.Theme) ([]byte, error)
 		if langColor == "" {
 			langColor = t.Accent
 		}
-		name := truncateName(r.Name, nameMax)
+		name := truncate(r.Name, nameMax)
 
 		fmt.Fprintf(&b, `
   <circle cx="%d" cy="%d" r="4" fill="%s"/>
@@ -100,12 +100,3 @@ func ownedNonForkRepos(repos []github.RepoInfo) []github.RepoInfo {
 	return out
 }
 
-// truncateName trims to n runes and appends an ellipsis. Operates on runes
-// so a multi-byte name (e.g. emoji) doesn't mid-cut.
-func truncateName(s string, n int) string {
-	r := []rune(s)
-	if len(r) <= n {
-		return s
-	}
-	return strings.TrimRight(string(r[:n-1]), ".") + "…"
-}