feat(studio): rich theme picker (presets + custom colour) + editor 0.11.0

Settings dialog's Theme Plugin section is now a grid of
swatched tiles:

- Built-in (none) — falls back to FaiTheme.light/.dark
- One tile per installed studio.theme.* plugin, each
  showing the plugin's primary/secondary/tertiary as
  live colour dots. Tile loads its preview lazily so a
  dozen installed themes don't block the picker.
- Custom — opens a colour-picker dialog with 12 curated
  Material presets + a hex input + live preview. Selecting
  applies ColorScheme.fromSeed for both brightnesses.

main.dart's _pluginThemes parses a 'custom:#RRGGBB' sigil
in the same notifier slot as plugin capability ids, so the
existing persistence + restoration paths cover the custom
case with no new state.

Bumps editor to 0.11.0 (type-checked port connections +
dynamic card width fix + card-height border allowance) and
Studio to 0.58.0.

Signed-off-by: flemming-it <stefan.a.flemming@googlemail.com>

lib/widgets/fai_flow_output.dart

@@ -126,10 +126,7 @@ class _CodeBlock extends StatelessWidget {
       ),
       child: SelectableText(
         text,
-        style: FaiTheme.mono(
-          size: 12,
-          color: theme.colorScheme.onSurface,
-        ),
+        style: FaiTheme.mono(size: 12, color: theme.colorScheme.onSurface),
       ),
     );
   }
@@ -170,14 +167,14 @@ class _BytesView extends StatelessWidget {
     try {
       await File(path).writeAsBytes(bytes, flush: true);
       if (!context.mounted) return;
-      ScaffoldMessenger.of(context).showSnackBar(
-        SnackBar(content: Text(l.flowsOutputSavedAt(path))),
-      );
+      ScaffoldMessenger.of(
+        context,
+      ).showSnackBar(SnackBar(content: Text(l.flowsOutputSavedAt(path))));
     } catch (e) {
       if (!context.mounted) return;
-      ScaffoldMessenger.of(context).showSnackBar(
-        SnackBar(content: Text(l.flowsOutputSaveFailed('$e'))),
-      );
+      ScaffoldMessenger.of(
+        context,
+      ).showSnackBar(SnackBar(content: Text(l.flowsOutputSaveFailed('$e'))));
     }
   }
 
@@ -239,9 +236,9 @@ class _FileView extends StatelessWidget {
     final r = await SystemActions.openInOs(target);
     if (!context.mounted || r.ok) return;
     final l = AppLocalizations.of(context)!;
-    ScaffoldMessenger.of(context).showSnackBar(
-      SnackBar(content: Text(l.flowsOutputOpenFailed(r.stderr))),
-    );
+    ScaffoldMessenger.of(
+      context,
+    ).showSnackBar(SnackBar(content: Text(l.flowsOutputOpenFailed(r.stderr))));
   }
 
   @override
@@ -261,10 +258,7 @@ class _FileView extends StatelessWidget {
         children: [
           SelectableText(
             uri,
-            style: FaiTheme.mono(
-              size: 11,
-              color: theme.colorScheme.primary,
-            ),
+            style: FaiTheme.mono(size: 11, color: theme.colorScheme.primary),
           ),
           if (mimeType.isNotEmpty) ...[
             const SizedBox(height: 4),