feat: Fully use protobuf, fix controller issues and cleanup (#305)

## Description
### First commit
Restructured protobuf schemas to make them easier to use across
languages, switched to using them in-place of JSON for signaling as
well, so there's no 2 different message formats flying about. Few new
message types to deal with clients and nestri-servers better (not final
format, may see changes still).

General cleanup of dead/unused code along some bug squashing and package
updates.

TODO for future commits:
- [x] Fix additional controllers not doing inputs (possibly needs
vimputti changes)
- [x] ~~Restructure relay protocols code a bit, to reduce bloatiness of
the currently single file for them, more code re-use.~~
- Gonna keep this PR somewhat manageable without poking more at relay..
- [x] ~~Try to fix issue where with multiple clients, static stream
content causes video to freeze until there's some movement.~~
- Was caused by server tuned profile being `throughput-performance`,
causing CPU latency to be too high.
- [x] Ponder the orb


### Second + third commit
Redid the controller polling handling and fixed multi-controller
handling in vimputti and nestri code sides. Remove some dead relay code
as well to clean up the protocol source file, we'll revisit the meshing
functionality later.

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **New Features**
* Added software rendering option and MangoHud runtime config;
controller sessions now support reconnection and batched state updates
with persistent session IDs.

* **Bug Fixes**
* Restored previously-filtered NES-like gamepads so they connect
correctly.

* **Chores**
* Modernized dependencies and protobuf tooling, migrated to
protobuf-based messaging and streaming, and removed obsolete CUDA build
steps.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Co-authored-by: DatCaptainHorse <DatCaptainHorse@users.noreply.github.com>

packages/relay/go.mod

@@ -10,7 +10,7 @@ require (
 	github.com/oklog/ulid/v2 v2.1.1
 	github.com/pion/ice/v4 v4.0.10
 	github.com/pion/interceptor v0.1.41
-	github.com/pion/rtp v1.8.24
+	github.com/pion/rtp v1.8.25
 	github.com/pion/webrtc/v4 v4.1.6
 	github.com/prometheus/client_golang v1.23.2
 	google.golang.org/protobuf v1.36.10
@@ -30,17 +30,17 @@ require (
 	github.com/gorilla/websocket v1.5.3 // indirect
 	github.com/hashicorp/golang-lru/v2 v2.0.7 // indirect
 	github.com/huin/goupnp v1.3.0 // indirect
-	github.com/ipfs/go-cid v0.5.0 // indirect
+	github.com/ipfs/go-cid v0.6.0 // indirect
 	github.com/jackpal/go-nat-pmp v1.0.2 // indirect
 	github.com/jbenet/go-temp-err-catcher v0.1.0 // indirect
-	github.com/klauspost/compress v1.18.0 // indirect
+	github.com/klauspost/compress v1.18.1 // indirect
 	github.com/klauspost/cpuid/v2 v2.3.0 // indirect
 	github.com/koron/go-ssdp v0.1.0 // indirect
 	github.com/libp2p/go-buffer-pool v0.1.0 // indirect
 	github.com/libp2p/go-flow-metrics v0.3.0 // indirect
 	github.com/libp2p/go-libp2p-asn-util v0.4.1 // indirect
 	github.com/libp2p/go-msgio v0.3.0 // indirect
-	github.com/libp2p/go-netroute v0.3.0 // indirect
+	github.com/libp2p/go-netroute v0.4.0 // indirect
 	github.com/libp2p/go-yamux/v5 v5.1.0 // indirect
 	github.com/libp2p/zeroconf/v2 v2.2.0 // indirect
 	github.com/marten-seemann/tcp v0.0.0-20210406111302-dfbc87cc63fd // indirect
@@ -71,13 +71,13 @@ require (
 	github.com/pion/sdp/v3 v3.0.16 // indirect
 	github.com/pion/srtp/v3 v3.0.8 // indirect
 	github.com/pion/stun v0.6.1 // indirect
-	github.com/pion/stun/v3 v3.0.0 // indirect
+	github.com/pion/stun/v3 v3.0.1 // indirect
 	github.com/pion/transport/v2 v2.2.10 // indirect
 	github.com/pion/transport/v3 v3.0.8 // indirect
-	github.com/pion/turn/v4 v4.1.1 // indirect
+	github.com/pion/turn/v4 v4.1.2 // indirect
 	github.com/prometheus/client_model v0.6.2 // indirect
-	github.com/prometheus/common v0.67.1 // indirect
-	github.com/prometheus/procfs v0.17.0 // indirect
+	github.com/prometheus/common v0.67.2 // indirect
+	github.com/prometheus/procfs v0.19.2 // indirect
 	github.com/quic-go/qpack v0.5.1 // indirect
 	github.com/quic-go/quic-go v0.55.0 // indirect
 	github.com/quic-go/webtransport-go v0.9.0 // indirect
@@ -91,12 +91,12 @@ require (
 	go.uber.org/zap v1.27.0 // indirect
 	go.yaml.in/yaml/v2 v2.4.3 // indirect
 	golang.org/x/crypto v0.43.0 // indirect
-	golang.org/x/exp v0.0.0-20251017212417-90e834f514db // indirect
+	golang.org/x/exp v0.0.0-20251023183803-a4bb9ffd2546 // indirect
 	golang.org/x/mod v0.29.0 // indirect
 	golang.org/x/net v0.46.0 // indirect
 	golang.org/x/sync v0.17.0 // indirect
 	golang.org/x/sys v0.37.0 // indirect
-	golang.org/x/telemetry v0.0.0-20251014153721-24f779f6aaef // indirect
+	golang.org/x/telemetry v0.0.0-20251028164327-d7a2859f34e8 // indirect
 	golang.org/x/text v0.30.0 // indirect
 	golang.org/x/time v0.14.0 // indirect
 	golang.org/x/tools v0.38.0 // indirect