fix(streaming): quote User-Agent header to prevent ffmpeg argument splitting

The ffmpeg -headers option was receiving the User-Agent value split across
multiple arguments due to spaces not being properly quoted. This caused ffmpeg
to interpret "Mozilla/5.0" as an output format, resulting in:
  [NULL @ ...] Unable to find a suitable output format for 'Mozilla/5.0'

Fixed by wrapping the entire headers string in quotes so parseArgsStringToArgv
treats it as a single argument. The headers string is now properly passed to
ffmpeg as: -headers "User-Agent: ... \r\nConnection: ..."

The fix has been applied to vendor/discord-video-stream/src/media/newApi.ts
and compiled into dist/media/newApi.js. A patch file and documentation have
been added to the patches/ directory for reference.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

patches/README.md

@@ -0,0 +1,35 @@
+# Patches
+
+This directory contains patches for vendor dependencies that have local modifications.
+
+## ffmpeg-headers-fix.patch
+
+**Issue:** Screen share streaming fails with ffmpeg error:
+```
+[NULL @ ...] Unable to find a suitable output format for 'Mozilla/5.0'
+```
+
+**Root Cause:** The `@dank074/discord-video-stream` library's `prepareStream` function passes HTTP headers to ffmpeg without proper quoting. The `fluent-ffmpeg-simplified` library uses `parseArgsStringToArgv` to parse command-line arguments, which splits strings by spaces. This causes the User-Agent header value (with spaces) to be split into multiple separate arguments instead of being kept as a single value.
+
+**Fix:** Wrap the entire headers string in quotes so `parseArgsStringToArgv` treats it as a single argument:
+```typescript
+// Before (broken)
+command.inputOptions(
+  "-headers",
+  Object.entries(customHeaders)
+    .map(([k, v]) => `${k}: ${v}`)
+    .join("\r\n"),
+);
+
+// After (fixed)
+const headersString = Object.entries(customHeaders)
+  .map(([k, v]) => `${k}: ${v}`)
+  .join("\r\n");
+command.inputOptions(`-headers "${headersString}"`);
+```
+
+**Applied To:** `vendor/discord-video-stream/src/media/newApi.ts` (lines 263-269)
+
+**Status:** Patch is applied locally. The compiled output in `dist/media/newApi.js` reflects this fix.
+
+**Note:** This is a local patch to the vendor submodule. To make this permanent, it should be submitted as a PR to the upstream repository: https://github.com/dank074/discord-video-stream

patches/ffmpeg-headers-fix.patch

@@ -0,0 +1,19 @@
+diff --git a/src/media/newApi.ts b/src/media/newApi.ts
+index original..modified 100644
+--- a/src/media/newApi.ts
++++ b/src/media/newApi.ts
+@@ -261,12 +261,10 @@ export function prepareStream(
+   if (isHttpUrl) {
+-    command.inputOptions(
+-      "-headers",
+-      Object.entries(customHeaders)
+-        .map(([k, v]) => `${k}: ${v}`)
+-        .join("\r\n"),
+-    );
++    const headersString = Object.entries(customHeaders)
++      .map(([k, v]) => `${k}: ${v}`)
++      .join("\r\n");
++    command.inputOptions(`-headers "${headersString}"`);
+     if (!isHls) {
+       command.inputOptions([
+         "-reconnect 1",