Stage 17 #2: extend the offline soft-disable to all server-action buttons

Following the in-game bar, the Connecting indicator now also visually disables the
other proactive (server-sending) controls while offline: chat send + nudge, profile
save / link email|telegram / merge-confirm, friends (redeem, get-code, accept/decline,
unfriend, block, unblock), New Game (auto-match variant + send-invitation) and the
lobby hide ❌. Purely local controls (board/rack/reset, menus, navigation, settings,
copy-code) stay live. Each reads the global connection.online signal; full e2e + check
green.

ui/src/screens/Profile.svelte

@@ -3,6 +3,7 @@
   import Modal from '../components/Modal.svelte';
   import Screen from '../components/Screen.svelte';
   import { app, applyLinkResult, handleError, logout, showToast } from '../lib/app.svelte';
+  import { connection } from '../lib/connection.svelte';
   import { gateway } from '../lib/gateway';
   import { loginWidgetAvailable, requestTelegramLogin } from '../lib/telegram';
   import { t } from '../lib/i18n/index.svelte';
@@ -209,7 +210,7 @@
             <span>{t('profile.notificationsInAppOnly')}</span>
           </label>
           <div class="formacts">
-            <button type="submit" class="btn" disabled={!formValid}>{t('common.save')}</button>
+            <button type="submit" class="btn" disabled={!formValid || !connection.online}>{t('common.save')}</button>
           </div>
         </form>
       {/if}
@@ -226,7 +227,7 @@
               placeholder={t('login.emailPlaceholder')}
               type="email"
             />
-            <button class="ghost" onclick={requestEmail} disabled={!emailOk}>{t('login.sendCode')}</button>
+            <button class="ghost" onclick={requestEmail} disabled={!emailOk || !connection.online}>{t('login.sendCode')}</button>
           </div>
         {:else}
           <div class="addrow">
@@ -237,11 +238,11 @@
               inputmode="numeric"
               maxlength="6"
             />
-            <button class="btn" onclick={confirmEmail}>{t('common.ok')}</button>
+            <button class="btn" onclick={confirmEmail} disabled={!connection.online}>{t('common.ok')}</button>
           </div>
         {/if}
         {#if telegramLinkable}
-          <button class="ghost tg" onclick={linkTelegram}>{t('profile.linkTelegram')}</button>
+          <button class="ghost tg" onclick={linkTelegram} disabled={!connection.online}>{t('profile.linkTelegram')}</button>
         {/if}
       </section>
 
@@ -257,7 +258,7 @@
       <p class="warn">{t('profile.mergeIrreversible')}</p>
       <div class="addrow end">
         <button class="ghost" onclick={() => (pendingMerge = null)}>{t('common.cancel')}</button>
-        <button class="btn" onclick={confirmMerge}>{t('profile.mergeConfirm')}</button>
+        <button class="btn" onclick={confirmMerge} disabled={!connection.online}>{t('profile.mergeConfirm')}</button>
       </div>
     </Modal>
   {/if}