fix(tui): prevent # and SSL columns from expanding unnecessarily

Set min=max for columns that don't benefit from extra width.
Surplus space goes to sparkline instead.

internal/tui/tab_sites.go

@@ -349,14 +349,14 @@ func (m Model) computeLayout() tableLayout {
 	}
 
 	cols := []colDef{
-		{"#", "#", 4, 6},
+		{"#", "#", 4, 4},
 		{"", "", 0, 0}, // NAME (dynamic)
 		{"TYPE", "TYPE", 8, 10},
 		{"STATUS", "STATUS", 8, 10},
 		{"LAT", "LATENCY", 7, 10},
 		{"UP%", "UPTIME", 8, 8},
 		{"", "", 0, 0}, // HISTORY (dynamic)
-		{"SSL", "SSL", 5, 7},
+		{"SSL", "SSL", 5, 5},
 		{"RT", "RETRIES", 5, 9},
 	}