feat: implement M1 teleport protocol sender

Stream a synthetic test pattern and silent PCM audio over the OBS
Teleport protocol:
- protocol: wire format (Header/ImageHeader/WaveHeader), BT.709 full
  range colour matrix, JPEG encode via turbojpeg cgo, WAVE packet builder
- output: TCP sender with per-connection buffered channels and drop-on-overflow
- discovery: multicast announce via peerdiscovery
- cmd: teleportfling CLI with flags, test-pattern frame generator

Verified end-to-end: OBS discovers and renders the stream with correct
colours and motion.

go.mod

@@ -0,0 +1,10 @@
+module teleportfling
+
+go 1.26.0
+
+require github.com/schollz/peerdiscovery v1.7.6
+
+require (
+	golang.org/x/net v0.59.0 // indirect
+	golang.org/x/sys v0.48.0 // indirect
+)