fix(nodes): stop flagging a node on the other update channel as outdated

A node's "update available" tag compares its reported panel version with the
master's latest, and any non-semver side fell back to string inequality. A
dev build reports dev+<sha> (config.GetPanelVersion), so a node moved to the
dev channel from a master on the stable channel kept the tag forever; the
reverse, a stable node under a master on the dev channel, was flagged too and
the tag's default stable update installed nothing new.

A dev label and a release tag carry no order, so the comparison now only
decides within one channel; dev-to-dev still compares commits, which keeps a
node on the current dev-latest commit untagged as config.go intends.

frontend/src/lib/panel-version.ts

@@ -28,6 +28,9 @@ export function formatPanelVersion(version: string | undefined | null): string {
 
 export function isPanelUpdateAvailable(latest: string, current: string): boolean {
   if (!latest || !current) return false;
+  // A dev+<sha> label and a release tag sit on different channels and carry no
+  // order, so a node moved to the other channel is not "behind" the master's latest.
+  if (latest.trim().startsWith('dev+') !== current.trim().startsWith('dev+')) return false;
   const a = parseVersionParts(latest);
   const b = parseVersionParts(current);
   if (!a || !b) {

frontend/src/test/panel-version.test.ts

@@ -30,6 +30,13 @@ describe('isPanelUpdateAvailable', () => {
     expect(isPanelUpdateAvailable('nightly-2', 'nightly-1')).toBe(true);
     expect(isPanelUpdateAvailable('nightly-1', 'nightly-1')).toBe(false);
   });
+
+  it('compares dev builds by commit and never across channels', () => {
+    expect(isPanelUpdateAvailable('dev+1a2b3c4d', 'dev+0f0f0f0f')).toBe(true);
+    expect(isPanelUpdateAvailable('dev+1a2b3c4d', 'dev+1a2b3c4d')).toBe(false);
+    expect(isPanelUpdateAvailable('v3.5.0', 'dev+1a2b3c4d')).toBe(false);
+    expect(isPanelUpdateAvailable('dev+1a2b3c4d', '3.5.0')).toBe(false);
+  });
 });
 
 describe('formatPanelVersion', () => {