fix: disable mic AGC by default to stop Windows audio crackle

Chromium's realtime AGC crackles on some Realtek/headset mics,
heard as repeated breaking and pitch warble. The no-agc fix
existed but was hidden behind an env var shipped builds never
set. Make it the default; volume is still restored offline via
the existing speechnorm/alimiter chain.

electron/ipc/register/settings.ts

@@ -21,7 +21,7 @@ import {
 import { parseJsonWithByteOrderMark } from "../utils";
 
 const BROWSER_MICROPHONE_PROFILE_ENV = "RECORDLY_BROWSER_MIC_PROFILE";
-const DEFAULT_BROWSER_MICROPHONE_PROFILE = "processed";
+const DEFAULT_BROWSER_MICROPHONE_PROFILE = "no-agc";
 const recordingPreferencesStore = createRecordingPreferencesStore(RECORDINGS_SETTINGS_FILE);
 const BROWSER_MICROPHONE_PROFILES = new Set([
 	"processed",

src/hooks/useScreenRecorder.test.ts

@@ -34,12 +34,12 @@ function createMockMediaRecorder(initialState: RecordingState = "inactive") {
 }
 
 describe("createProcessedMicrophoneConstraints", () => {
-	it("requests browser voice processing with AGC for the default microphone", () => {
+	it("requests browser voice processing without AGC for the default microphone", () => {
 		expect(createProcessedMicrophoneConstraints()).toEqual({
 			audio: {
 				echoCancellation: true,
 				noiseSuppression: true,
-				autoGainControl: true,
+				autoGainControl: false,
 				channelCount: { ideal: 1 },
 				sampleRate: { ideal: 48000 },
 			},
@@ -53,7 +53,7 @@ describe("createProcessedMicrophoneConstraints", () => {
 				deviceId: { exact: "device-123" },
 				echoCancellation: true,
 				noiseSuppression: true,
-				autoGainControl: true,
+				autoGainControl: false,
 				channelCount: { ideal: 1 },
 				sampleRate: { ideal: 48000 },
 			},
@@ -105,10 +105,10 @@ describe("createProcessedMicrophoneConstraints", () => {
 		});
 	});
 
-	it("normalizes invalid lab microphone profiles to production voice processing", () => {
+	it("normalizes invalid lab microphone profiles to the default voice processing", () => {
 		expect(normalizeBrowserMicrophoneProfile("RAW")).toBe("raw");
-		expect(normalizeBrowserMicrophoneProfile("unknown")).toBe("processed");
-		expect(normalizeBrowserMicrophoneProfile(null)).toBe("processed");
+		expect(normalizeBrowserMicrophoneProfile("unknown")).toBe("no-agc");
+		expect(normalizeBrowserMicrophoneProfile(null)).toBe("no-agc");
 	});
 });
 

src/hooks/useScreenRecorder.ts

@@ -51,7 +51,7 @@ export type BrowserCaptureCursorPolicy = {
 	hideOsCursorBeforeRecording: boolean;
 	hideEditorOverlayCursorByDefault: boolean;
 };
-const DEFAULT_BROWSER_MICROPHONE_PROFILE: BrowserMicrophoneProfile = "processed";
+const DEFAULT_BROWSER_MICROPHONE_PROFILE: BrowserMicrophoneProfile = "no-agc";
 const BROWSER_MICROPHONE_PROFILES = new Set<BrowserMicrophoneProfile>([
 	"processed",
 	"no-agc",