feat: quality profile selection in desktop settings

Adds a Quality dropdown (Auto / Opus 24k / Opus 6k / Codec2 3.2k /
Codec2 1.2k) to both the connect screen and settings panel. The
selected profile is passed through to the engine which configures
the encoder and decoder accordingly.

The desktop engine recv path now auto-switches the decoder codec
when incoming packets use a different codec than expected, enabling
cross-codec interop between clients on different quality settings.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

desktop/src/main.ts

@@ -8,6 +8,7 @@ const callScreen = document.getElementById("call-screen")!;
 const roomInput = document.getElementById("room") as HTMLInputElement;
 const aliasInput = document.getElementById("alias") as HTMLInputElement;
 const osAecCheckbox = document.getElementById("os-aec") as HTMLInputElement;
+const qualitySelect = document.getElementById("quality") as HTMLSelectElement;
 const connectBtn = document.getElementById("connect-btn") as HTMLButtonElement;
 const connectError = document.getElementById("connect-error")!;
 const roomName = document.getElementById("room-name")!;
@@ -48,6 +49,7 @@ const sRoom = document.getElementById("s-room") as HTMLInputElement;
 const sAlias = document.getElementById("s-alias") as HTMLInputElement;
 const sOsAec = document.getElementById("s-os-aec") as HTMLInputElement;
 const sAgc = document.getElementById("s-agc") as HTMLInputElement;
+const sQuality = document.getElementById("s-quality") as HTMLSelectElement;
 const sFingerprint = document.getElementById("s-fingerprint")!;
 const sRecentRooms = document.getElementById("s-recent-rooms")!;
 const sClearRecent = document.getElementById("s-clear-recent")!;
@@ -74,6 +76,7 @@ interface Settings {
   alias: string;
   osAec: boolean;
   agc: boolean;
+  quality: string;
   recentRooms: RecentRoom[];
 }
 
@@ -81,7 +84,7 @@ function loadSettings(): Settings {
   const defaults: Settings = {
     relays: [{ name: "Default", address: "193.180.213.68:4433" }],
     selectedRelay: 0, room: "android", alias: "",
-    osAec: true, agc: true, recentRooms: [],
+    osAec: true, agc: true, quality: "auto", recentRooms: [],
   };
   try {
     const raw = localStorage.getItem("wzp-settings");
@@ -156,6 +159,7 @@ function applySettings() {
   roomInput.value = s.room;
   aliasInput.value = s.alias;
   osAecCheckbox.checked = s.osAec;
+  qualitySelect.value = s.quality || "auto";
   renderRecentRooms(s.recentRooms);
   renderRelayButton();
 }
@@ -376,7 +380,7 @@ async function doConnect() {
   userDisconnected = false;
 
   const s = loadSettings();
-  s.room = roomInput.value; s.alias = aliasInput.value; s.osAec = osAecCheckbox.checked;
+  s.room = roomInput.value; s.alias = aliasInput.value; s.osAec = osAecCheckbox.checked; s.quality = qualitySelect.value;
   const room = roomInput.value.trim();
   if (room) {
     const entry: RecentRoom = { relay: relay.address, room };
@@ -388,6 +392,7 @@ async function doConnect() {
     await invoke("connect", {
       relay: relay.address, room: roomInput.value,
       alias: aliasInput.value, osAec: osAecCheckbox.checked,
+      quality: qualitySelect.value,
     });
     showCallScreen();
   } catch (e: any) {
@@ -529,7 +534,7 @@ listen("call-event", (event: any) => {
 // ── Settings ──
 function openSettings() {
   const s = loadSettings();
-  sRoom.value = s.room; sAlias.value = s.alias; sOsAec.checked = s.osAec;
+  sRoom.value = s.room; sAlias.value = s.alias; sOsAec.checked = s.osAec; sQuality.value = s.quality || "auto";
   sFingerprint.textContent = myFingerprint || "(loading...)";
   renderSettingsRecentRooms(s.recentRooms);
   settingsPanel.classList.remove("hidden");
@@ -564,9 +569,9 @@ settingsPanel.addEventListener("click", (e) => { if (e.target === settingsPanel)
 
 settingsSave.addEventListener("click", () => {
   const s = loadSettings();
-  s.room = sRoom.value; s.alias = sAlias.value; s.osAec = sOsAec.checked;
+  s.room = sRoom.value; s.alias = sAlias.value; s.osAec = sOsAec.checked; s.quality = sQuality.value;
   saveSettingsObj(s);
-  roomInput.value = s.room; aliasInput.value = s.alias; osAecCheckbox.checked = s.osAec;
+  roomInput.value = s.room; aliasInput.value = s.alias; osAecCheckbox.checked = s.osAec; qualitySelect.value = s.quality;
   renderRecentRooms(s.recentRooms);
   closeSettings();
 });