The dev server's manifest carries stage, heavy and widget, so Rudder's corner mounts under bun run dev

rega (7a7ca67b): on the dev server the corner widget never mounted, because /__plugin-gallery/manifest.json
built its profiles without the .meta.json fields only generate-tree read. Both now read them through one
module, internal/profile-meta.mjs (stage, heavy, widget per profile; bundle stage = production if any
profile says so), so the dev Studio and the built Studio cannot disagree. Verified: the dev model lists the
same 7 production bundles and rudder-voice:bottom-right; the built manifest is unchanged.

internal/generate-tree.mjs

@@ -44,6 +44,7 @@ import { createHash } from 'node:crypto'
 // without a separate tierMap. Previously the manifest carried no `type`, so a manifest-fed
 // consumer (plugin-studio) mis-tiered every profile as cap-1 (single). Single source of truth.
 import { detectProfileType } from './plugin-gallery/discover.mjs'
+import { profileMetaFields, bundleStage } from './profile-meta.mjs'
 import { TREE_NAME as CONFIGURED_TREE_NAME } from './_tree-name.mjs'
 import { syncAppShells } from './sync-app-shells.mjs'
 
@@ -301,25 +302,6 @@ function profileReachesAMap(dir, file) {
   }
   return false
 }
-/**
- * STAGE and HEAVY, read from <profile>.meta.json and carried into manifest.json (the Driver, 2026-09-27:
- * a public-but-unfinished plugin shows under EXPERIMENTAL in the Plugin Studio and the gallery until it works
- * as a production map). Both surfaces read the MANIFEST, so they cannot disagree, and neither keeps a list.
- *   "stage": "production" | "experimental"   default experimental; a bundle is production if ANY of its
- *                                             profiles says so (a bundle is one folder in the studio)
- *   "heavy": true                            the element holds live WebGL contexts, so a host must destroy
- *                                             it when it leaves the screen (Plugin Studio's HEAVY rows)
- */
-function metaStageHeavy(dir, profileName) {
-  try {
-    const meta = JSON.parse(readFileSync(join(dir, `${profileName}.meta.json`), 'utf8'))
-    const corner = meta?.widget?.corner
-    return { stage: meta?.stage === 'production' ? 'production' : 'experimental', heavy: meta?.heavy === true,
-      // "widget": { "corner": "bottom-right" } — a corner widget the Plugin Studio mounts once, fixed, not in a pane
-      widget: ['bottom-right', 'bottom-left', 'top-right', 'top-left'].includes(corner) ? { corner } : null }
-  } catch { return { stage: 'experimental', heavy: false, widget: null } }
-}
-
 function metaIsMap(dir, profileName) {
   try {
     const meta = JSON.parse(readFileSync(join(dir, `${profileName}.meta.json`), 'utf8'))
@@ -1305,12 +1287,9 @@ function scanBundles() {
           ? composesAMapLeaf(dir, profileName, file)
           : (metaIsMap(dir, profileName) ?? profileReachesAMap(dir, file))
 
-      const { stage: profileStage, heavy: profileHeavy, widget: profileWidget } = metaStageHeavy(dir, profileName)
       return {
         profile: profileName,
-        stage: profileStage,
-        ...(profileHeavy ? { heavy: true } : {}),
-        ...(profileWidget ? { widget: profileWidget } : {}),
+        ...profileMetaFields(dir, profileName),   // stage / heavy / widget, shared with the dev manifest
         file,
         description: description || fileTag || '',
         element: tag,
@@ -1364,7 +1343,7 @@ function scanBundles() {
       integrity,
       elements: bundleElements,
       ...(composesUnique.length ? { composes: composesUnique } : {}),
-      stage: profiles.some((p) => p.stage === 'production') ? 'production' : 'experimental',
+      stage: bundleStage(profiles),
       profiles,
     })
   }

internal/plugin-gallery/dev-plugin.mjs

@@ -16,6 +16,7 @@ import { readdirSync, statSync, existsSync, readFileSync } from 'node:fs'
 import { REPO_ROOT, discoverSpaRegistry } from './discover.mjs'
 import { readBuildConfig, renderGallery } from '../generate-gallery.mjs'
 import { TREE_NAME } from '../_tree-name.mjs'
+import { profileMetaFields, bundleStage } from '../profile-meta.mjs'
 
 // ─── DEV plugin gallery ──────────────────────────────────────────────────────
 // `bun x vite` (dev) serves the plugin gallery at `/` — the same page `bun run build`
@@ -115,6 +116,7 @@ export function galleryModel(reg) {
       const p = {
         profile, file: `${profile}.vue`, description: '', element: b.tag,
         type: typeOf.get(profile) || 'single',
+        ...profileMetaFields(resolve(REPO_ROOT, 'plugin-designs', b.bundle), profile),   // same as the built manifest
         iframeUrl: link(b.bundle, profile), scriptUrl,
         embed: {
           iframe: iframe(`./${b.bundle}/${profile}/index.html`),
@@ -135,7 +137,7 @@ export function galleryModel(reg) {
     // to drop them, so under the dev server — which is what the Driver's laptop runs — the studio's
     // Composed-of panel and composition trees were silently empty for every composite.
     const composes = [...new Set([...presets.keys()].flatMap((profile) => readComposes(b.bundle, profile)))]
-    return { bundle: b.bundle, scriptUrl, integrity: '', elements: [b.tag], ...(composes.length ? { composes } : {}), profiles }
+    return { bundle: b.bundle, scriptUrl, integrity: '', elements: [b.tag], stage: bundleStage(profiles), ...(composes.length ? { composes } : {}), profiles }
   })
   return {
     schema: 'doxa-maps-manifest@1', generatedFrom: 'plugin-designs/*/*.vue (dev discovery)', embedBase: '.',

internal/profile-meta.mjs

@@ -0,0 +1,35 @@
+/**
+ * profile-meta.mjs — the per-profile fields a host reads from <profile>.meta.json, in ONE place.
+ *
+ * generate-tree (the built manifest.json) and the dev server's /__plugin-gallery/manifest.json both call
+ * this, so the dev Studio and the built Studio cannot disagree (rega: the corner widget never mounted in
+ * dev because only the built manifest carried "widget").
+ *   stage   "production" | "experimental"   default experimental
+ *   heavy   true when the element holds live WebGL contexts
+ *   widget  { corner } for a corner widget the Plugin Studio mounts once, fixed
+ */
+import { readFileSync } from 'node:fs'
+import { join } from 'node:path'
+
+const CORNERS = ['bottom-right', 'bottom-left', 'top-right', 'top-left']
+
+export function readProfileMeta(dir, profileName) {
+  try {
+    const meta = JSON.parse(readFileSync(join(dir, `${profileName}.meta.json`), 'utf8'))
+    const corner = meta?.widget?.corner
+    return {
+      stage: meta?.stage === 'production' ? 'production' : 'experimental',
+      heavy: meta?.heavy === true,
+      widget: CORNERS.includes(corner) ? { corner } : null,
+    }
+  } catch { return { stage: 'experimental', heavy: false, widget: null } }
+}
+
+/** The optional manifest keys for one profile (stage always; heavy / widget only when set). */
+export function profileMetaFields(dir, profileName) {
+  const m = readProfileMeta(dir, profileName)
+  return { stage: m.stage, ...(m.heavy ? { heavy: true } : {}), ...(m.widget ? { widget: m.widget } : {}) }
+}
+
+/** A bundle is production if ANY of its profiles says so. */
+export const bundleStage = (profiles) => (profiles.some((p) => p.stage === 'production') ? 'production' : 'experimental')