refactor(tui): replace # column with colored status dot

Drop the row-number column and add a colored status dot as the first
column. Dot uses the same icon/color as the existing status indicators
(▲ green for up, ▼ red for down, ◼ purple for maint, etc). Matches
the maint strip visual pattern. Status text column retained for
explicit label.

internal/tui/tab_sites.go

@@ -37,6 +37,7 @@ const (
 	colDot colKey = iota
 	colName
 	colType
+	colStatus
 	colLatency
 	colUptime
 	colHistory
@@ -56,16 +57,15 @@ type columnDef struct {
 var siteColumns = []columnDef{
 	{colDot, "", "", 3, 3, 0},
 	{colName, "NAME", "NAME", 0, 0, 0},
-	{colType, "TYPE", "TYPE", 10, 8, 0},
+	{colType, "TYPE", "TYPE", 10, 8, mediumBreakpoint},
+	{colStatus, "STATUS", "STATUS", 10, 10, 0},
 	{colLatency, "LATENCY", "LAT", 10, 7, 0},
-	{colUptime, "UPTIME", "UP%", 8, 8, 0},
-	{colHistory, "HISTORY", "HISTORY", 0, 0, 0},
-	{colSSL, "SSL", "SSL", 7, 5, 0},
-	{colRetries, "RETRIES", "RT", 9, 5, 0},
+	{colUptime, "UPTIME", "UP%", 8, 8, mediumBreakpoint},
+	{colHistory, "HISTORY", "HISTORY", 0, 0, mediumBreakpoint},
+	{colSSL, "SSL", "SSL", 7, 5, wideBreakpoint},
+	{colRetries, "RETRIES", "RT", 9, 5, wideBreakpoint},
 }
 
-var columnDropOrder = []colKey{colHistory, colRetries, colSSL, colUptime, colType}
-
 type tableLayout struct {
 	nameW, sparkW int
 	headers       []string
@@ -76,51 +76,17 @@ type tableLayout struct {
 func (m Model) computeLayout() tableLayout {
 	wide := m.isWide()
 
-	cw := m.contentWidth
-	if cw == 0 {
-		cw = m.termWidth
-	}
-
-	dropped := make(map[colKey]bool)
-	minNameW := 20
-	minSparkW := 12
-
-	for attempt := 0; attempt <= len(columnDropOrder); attempt++ {
-		var fixed int
-		var flexCount int
-		for _, c := range siteColumns {
-			if dropped[c.key] {
-				continue
-			}
-			w := c.narrowW
-			if wide {
-				w = c.wideW
-			}
-			if w > 0 {
-				fixed += w
-			} else {
-				flexCount++
-			}
-		}
-		numCols := len(siteColumns) - len(dropped)
-		borderOverhead := 2 + (numCols - 1)
-		avail := cw - chromePadH - 2 - borderOverhead - fixed
-		minFlex := minNameW
-		if flexCount > 1 {
-			minFlex += minSparkW
-		}
-		if avail >= minFlex || attempt >= len(columnDropOrder) {
-			break
-		}
-		dropped[columnDropOrder[attempt]] = true
-	}
-
 	var active []colKey
 	var headers []string
 	var widths []int
 	var fixed int
+
+	cw := m.contentWidth
+	if cw == 0 {
+		cw = m.termWidth
+	}
 	for _, c := range siteColumns {
-		if dropped[c.key] {
+		if c.minTerm > 0 && cw < c.minTerm {
 			continue
 		}
 		active = append(active, c.key)
@@ -140,12 +106,12 @@ func (m Model) computeLayout() tableLayout {
 	}
 
 	sortColMap := map[int]colKey{
-		sortStatus:  colDot,
+		sortStatus:  colStatus,
 		sortName:    colName,
 		sortLatency: colLatency,
 	}
 	sortableKeys := map[colKey]string{
-		colDot:     "sort-status",
+		colStatus:  "sort-status",
 		colName:    "sort-name",
 		colLatency: "sort-latency",
 	}
@@ -284,6 +250,7 @@ func (m Model) viewSitesTab() string {
 						colDot:     m.fmtStatusDot(site.Status, site.Paused, inMaint),
 						colName:    m.zones.Mark(fmt.Sprintf("site-%d", i), icon+" "+limitStr(site.Name, nameW-4)),
 						colType:    "group",
+						colStatus:  m.fmtStatus(site.Status, site.Paused, inMaint),
 						colLatency: m.st.subtleStyle.Render("—"),
 						colUptime:  m.groupUptime(site.ID),
 						colHistory: m.groupSparkline(site.ID, sparkWidth, rowBg),
@@ -332,6 +299,7 @@ func (m Model) viewSitesTab() string {
 					colDot:     m.fmtStatusDot(site.Status, site.Paused, inMaint),
 					colName:    m.zones.Mark(fmt.Sprintf("site-%d", i), name),
 					colType:    typeIcon(site.Type, false) + " " + site.Type,
+					colStatus:  m.fmtStatus(site.Status, site.Paused, inMaint),
 					colLatency: m.fmtLatency(site.Latency),
 					colUptime:  m.fmtUptimeMaint(hist.Statuses, site.ID),
 					colHistory: spark,