chore: replace Ko-Fi with Support links, drop uninstall token

Switch the Ko-Fi support links to https://support.koalastuff.net across the
README badge, the extension footer (popup.html/template.html, label
"Support KoalaSync") and remove the now-unused KOFI_URL constant. Stop
generating/sending the anonymous uninstall token: initUninstallURL() now
registers the feedback URL without the `t` parameter or storage write.
CHANGELOG updated to match.

Also guard the client CMD_ACK path: only ACK a command sender that is still
a known peer in the room, so we don't emit ACKs to peers that already left
(which the server now drops as absent-peer ACKs anyway).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

README.md

@@ -138,7 +138,7 @@ gh attestation verify dist/koalasync-chrome.zip \
 ---
 
 <div align="center">
-  <sub><a href="https://ko-fi.com/koaladev"><img src="https://img.shields.io/badge/Ko--Fi-Support-FF5E5B?logo=ko-fi&logoColor=white" alt="Ko-Fi"></a></sub>
+  <sub><a href="https://support.koalastuff.net"><img src="https://img.shields.io/badge/Support-KoalaSync-FF5E5B" alt="Support KoalaSync"></a></sub>
   <sub><a href="https://gitgem.org/github/Shik3i/KoalaSync"><img src="https://gitgem.org/api/badge/github/Shik3i/KoalaSync.svg" alt="GitGem Badge" /></a></sub>
 
   <sub>Built with ❤️ by <a href="https://github.com/Shik3i">Shik3i</a>. KoalaSync is Open Source under the <a href="LICENSE">MIT License</a>.</sub>

docs/CHANGELOG.md

@@ -7,7 +7,7 @@ All notable changes to the KoalaSync browser extension and relay server.
 ## [v2.4.2] — 2026-06-19
 
 ### Changed
-- **Extension: Optimized uninstall URL registration** — Extracted registration into a reusable, race-condition-protected `initUninstallURL()` helper. It now generates a unique, anonymous token (`t`) stored in `chrome.storage.local` to securely track uninstalls, and registers the URL on both extension installation/update and browser startup to prevent state loss.
+- **Extension: Optimized uninstall URL registration** — Extracted registration into a reusable, race-condition-protected `initUninstallURL()` helper. It registers the uninstall feedback URL with browser context on both extension installation/update and browser startup to prevent state loss, without storing or sending an installation token.
 
 ## [v2.4.1] — 2026-06-19
 
@@ -149,7 +149,7 @@ All notable changes to the KoalaSync browser extension and relay server.
 - **Feature Hint System**: Generic `dismissedHints` array in sync storage for announcing new features. First hint highlights the Audio Options entry in Settings. Extensible for future features.
 
 ### Changed
-- **Ko-Fi Support Links**: Static footer badges on the Settings and Status tabs linking to the developer's support page. README and website footer updated with Ko-Fi badge.
+- **Support Links**: Static footer badges on the Settings and Status tabs linking to the developer's support page. README and website footer updated with a Support KoalaSync badge.
 
 ### Fixed
 - **Portuguese (PT) locale**: Removed Italian contamination — "sincronizzazione" → "sincronização", "tempo reale" → "tempo real", "Link di Invito" → "Link de Convite", "Sair della Sala" → "Sair da Sala".

extension/background.js

@@ -19,24 +19,8 @@ async function initUninstallURL() {
         
         if (UNINSTALL_URL && UNINSTALL_URL.trim() !== '') {
             try {
-                if (typeof chrome === 'undefined' || !chrome.storage || !chrome.storage.local) {
-                    console.warn("Storage API not available, skipping uninstall URL token generation");
-                    return;
-                }
-
-                const data = await chrome.storage.local.get("koalaByeToken");
-                let token = data?.koalaByeToken;
-                
-                if (!token) {
-                    token = (typeof self.crypto !== 'undefined' && typeof self.crypto.randomUUID === 'function')
-                        ? self.crypto.randomUUID()
-                        : Math.random().toString(36).substring(2, 15) + Math.random().toString(36).substring(2, 15);
-                    await chrome.storage.local.set({ koalaByeToken: token });
-                }
-
                 const url = new URL(UNINSTALL_URL);
                 url.searchParams.set("browser", BROWSER_TYPE);
-                url.searchParams.set("t", token);
                 
                 const runtimeAPI = typeof browser !== 'undefined' ? browser.runtime : chrome.runtime;
                 if (runtimeAPI && runtimeAPI.setUninstallURL) {
@@ -1751,11 +1735,16 @@ async function handleAsyncMessage(message, sender, sendResponse) {
         sendResponse({ status: 'ok' });
     } else if (message.type === 'CMD_ACK') {
         const commandSenderId = message.commandSenderId;
-        if (commandSenderId && commandSenderId !== peerId) {
-            emit(EVENTS.EVENT_ACK, { 
-                senderId: peerId, 
+        // Only ACK if the command sender is still a known peer in our room.
+        // If we've already seen their PEER_STATUS 'left', skip the ACK — it would
+        // only be dropped server-side as an absent-peer ACK anyway.
+        const senderStillPresent = currentRoom && Array.isArray(currentRoom.peers) &&
+            currentRoom.peers.some(p => (typeof p === 'object' ? p.peerId : p) === commandSenderId);
+        if (commandSenderId && commandSenderId !== peerId && senderStillPresent) {
+            emit(EVENTS.EVENT_ACK, {
+                senderId: peerId,
                 targetId: commandSenderId,
-                actionTimestamp: message.actionTimestamp 
+                actionTimestamp: message.actionTimestamp
             });
         }
         sendResponse({ status: 'ok' });

shared/constants.js

@@ -13,7 +13,6 @@ export const OFFICIAL_SERVER_URL = 'wss://syncserver.koalastuff.net';
 export const OFFICIAL_LANDING_PAGE_URL = 'https://sync.koalastuff.net';
 export const OFFICIAL_SERVER_TOKEN = '62170b705234c4f4807a9b22420bb93cf1a2aacfa4c5d3b47804482babb8eb50';
 export const SUPPORT_URL = 'https://support.koalastuff.net';
-export const KOFI_URL = 'https://ko-fi.com/koaladev';
 export const GITHUB_URL = 'https://github.com/Shik3i/KoalaSync';
 
 export function isFirefox() {