fix(dashboard): keep selection visible against active-line tint

CodeMirror layers the active-line background above the selection layer,
so the previous opaque active-line color hid selections on the current
line. Bumps selection alpha and switches active-line to a subtle sky
tint, with the brighter gutter line number as the primary cue.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

dashboard/src/lib/editor-theme.ts

@@ -17,8 +17,19 @@ const palette = {
 	text: '#e2e8f0',
 	textMuted: '#94a3b8',
 	cursor: '#38bdf8',
-	selection: '#38bdf830',
-	activeLine: '#1e293b',
+	// Selection alpha was originally 30 (≈19%) — bumped to 55 (≈33%)
+	// so it stays clearly visible when it sits on top of (or under, in
+	// CodeMirror's case) the active-line tint. The default CM layering
+	// puts the selection layer behind line backgrounds, so an opaque
+	// active line hides selections on the current line; this pair of
+	// values makes both visible at once.
+	selection: '#38bdf855',
+	// Active line: very subtle sky tint at ~6% alpha. Strong enough to
+	// see at a glance which line the caret is on, weak enough to leave
+	// the selection visible underneath. The active-line gutter (the
+	// brighter line number on the left) is the primary indicator.
+	activeLine: '#38bdf810',
+	activeLineGutter: '#1e293b',
 	matchingBracket: '#38bdf850',
 	searchMatch: '#38bdf850',
 	searchMatchSelected: '#38bdf8',
@@ -76,7 +87,7 @@ export const dashboardTheme = EditorView.theme(
 			borderRight: `1px solid ${palette.border}`
 		},
 		'.cm-activeLineGutter': {
-			backgroundColor: palette.activeLine,
+			backgroundColor: palette.activeLineGutter,
 			color: palette.text
 		},
 		'.cm-matchingBracket, .cm-nonmatchingBracket': {