fix(framework): savePreferences returns the typed error on a failed write

.changeset/save-preferences-result.md

@@ -0,0 +1,5 @@
+---
+'@gemstack/framework': patch
+---
+
+Fix `savePreferences` rejecting the RPC when the underlying write fails. The telefunction advertises a `{ ok: false, error }` result and already returns it for the not-enabled case, but a failed disk write threw straight through, so the client saw a rejected call instead of the typed error. The write is now wrapped, so both failure modes return `{ ok: false }` and the client handles them the same way.

packages/framework/src/dashboard-rpc/preferences.telefunc.test.ts

@@ -1,6 +1,8 @@
 import { strict as assert } from 'node:assert'
 import { test } from 'node:test'
+import { provideTelefuncContext } from 'telefunc'
 import { onPreferences, savePreferences } from './preferences.telefunc.js'
+import type { PreferencesStore } from '../registry.js'
 
 // Outside a Telefunc `serve({ context })` there is no preferences store on the context — the
 // same situation as the public relay, which never wires one. The RPCs must degrade safely: a
@@ -15,3 +17,15 @@ test('savePreferences with no store is a not-enabled no-op', async () => {
   const result = await savePreferences({ autopilot: false })
   assert.deepEqual(result, { ok: false, error: 'preferences are not enabled on this server' })
 })
+
+test('savePreferences returns the typed error when the store write fails, not a rejection', async () => {
+  const store: PreferencesStore = {
+    read: async () => ({}),
+    save: async () => {
+      throw new Error('disk full')
+    },
+  }
+  provideTelefuncContext({ preferences: store })
+  const result = await savePreferences({ autopilot: true })
+  assert.deepEqual(result, { ok: false, error: 'failed to save preferences' })
+})

packages/framework/src/dashboard-rpc/preferences.telefunc.ts

@@ -22,6 +22,12 @@ export async function onPreferences(): Promise<Preferences> {
 export async function savePreferences(preferences: Preferences): Promise<SavePreferencesResult> {
   const store = contextPreferences()
   if (!store) return { ok: false, error: 'preferences are not enabled on this server' }
-  await store.save(preferences)
-  return { ok: true }
+  // A failed write returns the advertised typed error rather than rejecting the RPC,
+  // so the client handles it the same as the not-enabled case (both `{ ok: false }`).
+  try {
+    await store.save(preferences)
+    return { ok: true }
+  } catch {
+    return { ok: false, error: 'failed to save preferences' }
+  }
 }