fix(update): compare core versions using SemVer

Only show update indicators when the remote core version is newer.
Add coverage for prereleases, build metadata, invalid versions, and version boundaries.

src/coreUpdate.tsx

@@ -35,13 +35,66 @@ function normalizeVersion(version: string | null | undefined) {
   return (version ?? '').trim().replace(/^v/i, '');
 }
 
+type SemanticVersion = {
+  core: [string, string, string];
+  prerelease: string[] | null;
+};
+
+const semanticVersionPattern = /^(0|[1-9]\d*)\.(0|[1-9]\d*)\.(0|[1-9]\d*)(?:-((?:0|[1-9]\d*|\d*[A-Za-z-][0-9A-Za-z-]*)(?:\.(?:0|[1-9]\d*|\d*[A-Za-z-][0-9A-Za-z-]*))*))?(?:\+[0-9A-Za-z-]+(?:\.[0-9A-Za-z-]+)*)?$/;
+
+function parseSemanticVersion(version: string | null | undefined): SemanticVersion | null {
+  const match = semanticVersionPattern.exec(normalizeVersion(version));
+  if (!match) return null;
+
+  return {
+    core: [match[1], match[2], match[3]],
+    prerelease: match[4] ? match[4].split('.') : null,
+  };
+}
+
+function compareNumericIdentifier(left: string, right: string) {
+  if (left.length !== right.length) return left.length > right.length ? 1 : -1;
+  if (left === right) return 0;
+  return left > right ? 1 : -1;
+}
+
+function compareSemanticVersions(left: SemanticVersion, right: SemanticVersion) {
+  for (let index = 0; index < left.core.length; index += 1) {
+    const difference = compareNumericIdentifier(left.core[index], right.core[index]);
+    if (difference !== 0) return difference;
+  }
+
+  if (left.prerelease === null) return right.prerelease === null ? 0 : 1;
+  if (right.prerelease === null) return -1;
+
+  const count = Math.max(left.prerelease.length, right.prerelease.length);
+  for (let index = 0; index < count; index += 1) {
+    const leftIdentifier = left.prerelease[index];
+    const rightIdentifier = right.prerelease[index];
+    if (leftIdentifier === undefined) return -1;
+    if (rightIdentifier === undefined) return 1;
+    if (leftIdentifier === rightIdentifier) continue;
+
+    const leftIsNumeric = /^\d+$/.test(leftIdentifier);
+    const rightIsNumeric = /^\d+$/.test(rightIdentifier);
+    if (leftIsNumeric && rightIsNumeric) {
+      return compareNumericIdentifier(leftIdentifier, rightIdentifier);
+    }
+    if (leftIsNumeric) return -1;
+    if (rightIsNumeric) return 1;
+    return leftIdentifier > rightIdentifier ? 1 : -1;
+  }
+
+  return 0;
+}
+
 export function coreUpdateAvailable(
   currentVersion: string | null | undefined,
   latestVersion: string | null | undefined,
 ) {
-  const current = normalizeVersion(currentVersion);
-  const latest = normalizeVersion(latestVersion);
-  return Boolean(current && latest && current !== latest);
+  const current = parseSemanticVersion(currentVersion);
+  const latest = parseSemanticVersion(latestVersion);
+  return Boolean(current && latest && compareSemanticVersions(latest, current) > 0);
 }
 
 export function requestLatestCore(force = false) {

src/pages/VersionManagementPage.tsx

@@ -742,7 +742,7 @@ export function VersionManagementPage() {
 
             <button
               type="button"
-              className={latestVersion && (!coreInstalled || currentVersion !== latestVersion) ? 'primary-button' : 'secondary-button'}
+              className={latestVersion && (!coreInstalled || coreHasUpdate) ? 'primary-button' : 'secondary-button'}
               title={latestVersion ? t('kernel.versions.stopAndUpdateVersion', { version: latestVersion }) : t('kernel.versions.installLatest')}
               disabled={!latestVersion || busy}
               onClick={() => setConfirmUpdateOpen(true)}