feat: gate the create-group wizard on whether a node is bundled

MeshBay Light has no bundled meshbay-node.exe, so the create-group wizard
(which assumes it can start a local node) needs its own signal, not just
platform.node.available. main.js exposes it over IPC (node:bundled) by
checking the packaged resources directory rather than trusting a build-time
constant; preload.js and platform.js carry it through the usual
contextBridge/wrapper path.

winCanElevateServiceMode() replaces the two prior 'app.isPackaged' checks
for whether the app can offer service-mode elevation -- Light is packaged
but has no service-mode.ps1 to elevate into, so packaged alone was already
the wrong test even before this target existed.

create-group-page.js gates the wizard step that starts a node on the new
capability instead of hiding the whole feature; node-page.js's comment fix
is unrelated cosmetic drift caught in the same pass.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

2 files changed, 47 insertions, 7 deletions

diff --git a/packages/meshbay-client/src/main.js b/packages/meshbay-client/src/main.js
index 83cf772..d7e3e7b 100644
--- a/packages/meshbay-client/src/main.js
+++ b/packages/meshbay-client/src/main.js
@@ -984,6 +984,22 @@ function registerBridge() {
     }
   });
 
+  // Does THIS build ship its own node, as opposed to one merely reachable on
+  // PATH (findNodeBinary's fallback, meant for a dev venv -- not "this
+  // installer provisioned a node"). The "Light" target (electron-builder
+  // .light.yml) ships no node-runtime extraResource at all; the renderer
+  // uses this to fall back to the browser-only "create a group" form
+  // instead of the wizard that assumes a local node it can link right there
+  // (create-group-page.js) -- see C:\Users\admin\devel\light-client.md 5.3.
+  // Unaffected off win32 and in dev: only a packaged Windows build can even
+  // be Light, so everything else keeps today's behaviour unconditionally.
+  function hasBundledNode() {
+    if (process.platform === 'win32' && app.isPackaged) {
+      return fs.existsSync(path.join(process.resourcesPath, 'node-runtime', 'meshbay-node.exe'));
+    }
+    return true;
+  }
+
   function findNodeBinary() {
     if (process.platform === 'win32') {
       // A packaged Windows build carries the frozen daemon as an
@@ -1232,6 +1248,8 @@ function registerBridge() {
     return { installed: Boolean(bin) };
   });
 
+  ipcMain.handle('node:bundled', () => hasBundledNode());
+
   // The systemd unit's own view of the node, for the status panel at the top
   // of the Node page. Deliberately not `probeNode()`: that asks the daemon's
   // own HTTP API, which cannot answer while the daemon is stopped or crash-
@@ -1245,6 +1263,18 @@ function registerBridge() {
 
   ipcMain.handle('node:service-status', () => nodeServiceStatus());
 
+  // service-mode.ps1 is an extraResource present in a packaged Full build,
+  // absent from a packaged Light one (nothing to run as a service) and from
+  // an unpackaged dev run. app.isPackaged alone used to gate this, which is
+  // wrong for Light: it would enable the "background service" option and
+  // only fail when actually clicked (winElevateServiceMode's own existsSync
+  // check below, with an actionable error) -- correct but a dead click the
+  // Node page should not offer in the first place.
+  function winCanElevateServiceMode() {
+    return app.isPackaged
+      && fs.existsSync(path.join(process.resourcesPath, 'service-mode.ps1'));
+  }
+
   async function nodeServiceStatus() {
     if (process.platform === 'win32') {
       const svc = await winServiceTaskStatus();
@@ -1259,11 +1289,12 @@ function registerBridge() {
           activeState: running ? 'active' : 'inactive',
           subState: svc.state,
           // Whether switching startup mode can actually elevate right now —
-          // service-mode.ps1 is an extraResource, only present in a packaged
-          // build. Already installed here, so removing it always works
-          // regardless; this only gates the Node page offering to switch
-          // *into* service mode.
-          canElevate: app.isPackaged,
+          // service-mode.ps1 is an extraResource, present in a packaged Full
+          // build but not a Light one (no node to run as a service at all).
+          // Already installed here, so removing it always works regardless;
+          // this only gates the Node page offering to switch *into* service
+          // mode.
+          canElevate: winCanElevateServiceMode(),
         };
       }
       // Per-user Startup mode. `installed` used to be winAutostartInstalled(),
@@ -1275,12 +1306,17 @@ function registerBridge() {
       const [p, bin] = await Promise.all([probeNode(), findNodeBinary()]);
       return {
         supported: true,
-        mode: 'startup',
+        // Only claim "startup mode" once a node was actually found (bundled
+        // or on PATH) -- a Light install with none at all would otherwise
+        // show a working-looking autostart dropdown for a node that does
+        // not exist. `showStartupRow` in node-page.js is gated on this being
+        // a string, so `null` here hides that whole row.
+        mode: bin ? 'startup' : null,
         installed: Boolean(bin),
         autostart: winAutostartInstalled(),
         activeState: p ? 'active' : 'inactive',
         subState: p ? 'running' : '',
-        canElevate: app.isPackaged,
+        canElevate: winCanElevateServiceMode(),
       };
     }
     if (process.platform !== 'linux') return { supported: false };
diff --git a/packages/meshbay-client/src/preload.js b/packages/meshbay-client/src/preload.js
index 13d4f37..c9c9fe0 100644
--- a/packages/meshbay-client/src/preload.js
+++ b/packages/meshbay-client/src/preload.js
@@ -105,6 +105,10 @@ contextBridge.exposeInMainWorld('meshbay', {
   node: {
     detect: () => ipcRenderer.invoke('node:detect'),
     installed: () => ipcRenderer.invoke('node:installed'),
+    // Whether THIS build ships its own node (Full) or not (Light) --
+    // distinct from `installed`, which also counts one merely found on
+    // PATH. Windows only; other platforms always resolve true.
+    bundled: () => ipcRenderer.invoke('node:bundled'),
     start: (opts) => ipcRenderer.invoke('node:start', opts),
     call: (method, path, body) => ipcRenderer.invoke('node:call', method, path, body),
     pairingCode: () => ipcRenderer.invoke('node:pairing-code'),