fix(publish): advance @next dist-tag after stable release

When a stable release publishes via workflow_dispatch, @latest can leapfrog
the existing @next prerelease (e.g. latest=6.5.0 while next=6.4.1-next.0),
turning `npx bmad-method@next install` into a silent downgrade until the
next qualifying push to main republishes a fresh -next.0.

- publish.yaml: after stable publish, repoint @next at the just-published
  stable version. The existing derive-prerelease step picks max(latest, next)
  as its base, so subsequent push-driven prereleases bump from there.
- bmad-cli.js: checkForUpdate was querying the @beta dist-tag (which this
  package does not use). Replace string-matching with semver.prerelease()
  and query @next for prerelease users.

.github/workflows/publish.yaml

@@ -135,6 +135,17 @@ jobs:
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 
+      - name: Advance @next dist-tag to stable
+        if: github.event_name == 'workflow_dispatch' && inputs.channel == 'latest'
+        run: |
+          # Without this, @latest can leapfrog @next (e.g. latest=6.5.0 while
+          # next=6.4.1-next.0) and `npx bmad-method@next install` silently
+          # downgrades users. Point @next at the just-published stable so
+          # @next >= @latest always holds; the next push-driven prerelease will
+          # bump from this base via the existing derive step above.
+          VERSION=$(node -p 'require("./package.json").version')
+          npm dist-tag add "bmad-method@${VERSION}" next
+
       - name: Notify Discord
         if: github.event_name == 'workflow_dispatch' && inputs.channel == 'latest'
         continue-on-error: true

tools/installer/bmad-cli.js

@@ -23,13 +23,10 @@ checkForUpdate().catch(() => {
 
 async function checkForUpdate() {
   try {
-    // For beta versions, check the beta tag; otherwise check latest
+    // Prereleases (e.g. 6.5.1-next.0) live on the `next` dist-tag; stable
-    const isBeta =
+    // releases live on `latest`. semver.prerelease() returns null for stable,
-      packageJson.version.includes('Beta') ||
+    // so this correctly routes pre-1.0-next/rc/etc. without string matching.
-      packageJson.version.includes('beta') ||
+    const tag = semver.prerelease(packageJson.version) ? 'next' : 'latest';
-      packageJson.version.includes('alpha') ||
-      packageJson.version.includes('rc');
-    const tag = isBeta ? 'beta' : 'latest';
 
     const result = execSync(`npm view ${packageName}@${tag} version`, {
       encoding: 'utf8',