feat(ui): colour the fixed-view icons, lift the notes surfaces, fix the create header

Following the Things pass, four bits of polish:

- The fixed views carry their own colour — amber star for Today, blue tray
  for the Inbox, red Upcoming, violet Waiting on others, teal Notes, indigo
  Calendar — and keep it whether or not they are the active row.
- The active row was all but invisible on the dark sidebar (a half-step of
  surface); it is now an accent-tinted selection that reads in both themes.
- The Projekter heading — the only place to add a project or a group — no
  longer scrolls away with a long list; it is pinned to the top of the
  scroller.
- The note list and the editor lift off the page: white in light, a nuance
  lighter than the ground in dark, so the two read as one writing surface.

Screenshots regenerated.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

web/src/routes/noter/+page.svelte

@@ -1081,6 +1081,11 @@
 		min-width: 0;
 		border-right: 1px solid var(--line);
 		padding-right: var(--s3);
+		/* White in light, a nuance lighter than the ground in dark — the note list
+		   is a surface you read down, so it lifts off the page like the editor does.
+		   --surface-raised is #fff in the light themes and one step up in the dark. */
+		background: var(--surface-raised);
+		padding-left: var(--s3);
 	}
 
 	.head {
@@ -1546,7 +1551,9 @@
 		flex-direction: column;
 		min-height: 0;
 		min-width: 0;
-		background: var(--surface);
+		/* A nuance lighter than the ground in dark, still white in light — matches
+		   the note list beside it so the two read as one writing surface. */
+		background: var(--surface-raised);
 		border: 1px solid var(--line);
 		border-radius: var(--radius);
 		/* Luft nok til at teksten ikke rører kanten.