feat: add shared streaming constants module

packages/shared/package.json

@@ -10,7 +10,9 @@
     "./src/permissions": "./src/permissions.ts",
     "./src/permissions.js": "./src/permissions.ts",
     "./src/activities": "./src/activities.ts",
-    "./src/activities.js": "./src/activities.ts"
+    "./src/activities.js": "./src/activities.ts",
+    "./src/constants": "./src/constants.ts",
+    "./src/constants.js": "./src/constants.ts"
   },
   "scripts": {
     "build": "tsc",

packages/shared/src/constants.ts

@@ -0,0 +1,30 @@
+// ─── Streaming Constants ─────────────────────────────────────────────────────
+
+export const STANDARD_RESOLUTIONS = [540, 720, 1080, 1440, 2160] as const;
+export type StandardResolution = (typeof STANDARD_RESOLUTIONS)[number];
+export type Resolution = StandardResolution | 'native';
+
+export const ALL_RESOLUTIONS: readonly Resolution[] = [...STANDARD_RESOLUTIONS, 'native'];
+
+export const STANDARD_FRAMERATES = [30, 45, 60, 75, 90, 120] as const;
+export type Framerate = (typeof STANDARD_FRAMERATES)[number];
+
+export const WIDTH_MAP: Record<StandardResolution, number> = {
+  540: 960,
+  720: 1280,
+  1080: 1920,
+  1440: 2560,
+  2160: 3840,
+};
+
+export const RESOLUTION_LABELS: Record<Resolution, string> = {
+  540: '540p',
+  720: '720p',
+  1080: '1080p',
+  1440: '1440p',
+  2160: '4K',
+  native: 'Native',
+};
+
+export const HIGH_END_RESOLUTION_THRESHOLD = 1440;
+export const HIGH_END_FRAMERATE_THRESHOLD = 75;