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/scripts/entrypoint.sh

@@ -15,13 +15,13 @@ NVIDIA_INSTALLER_DIR="/tmp"
 TIMEOUT_SECONDS=10
 ENTCMD_PREFIX=""
 
-# Ensures user directory ownership
-chown_user_directory() {
+# Ensures user ownership across directories
+handle_user_permissions() {
     if ! $ENTCMD_PREFIX chown "${NESTRI_USER}:${NESTRI_USER}" "${NESTRI_HOME}" 2>/dev/null; then
         echo "Error: Failed to change ownership of ${NESTRI_HOME} to ${NESTRI_USER}:${NESTRI_USER}" >&2
         return 1
     fi
-    # Also apply to .cache separately
+    # Also apply to .cache
     if [[ -d "${NESTRI_HOME}/.cache" ]]; then
         if ! $ENTCMD_PREFIX chown "${NESTRI_USER}:${NESTRI_USER}" "${NESTRI_HOME}/.cache" 2>/dev/null; then
             echo "Error: Failed to change ownership of ${NESTRI_HOME}/.cache to ${NESTRI_USER}:${NESTRI_USER}" >&2
@@ -324,9 +324,23 @@ main() {
         log "Skipping CAP_SYS_NICE for gamescope, capability not available"
     fi
 
-    # Handle user directory permissions
-    log "Ensuring user directory permissions..."
-    chown_user_directory || exit 1
+    # Make sure /tmp/.X11-unix exists..
+    if [[ ! -d "/tmp/.X11-unix" ]]; then
+        log "Creating /tmp/.X11-unix directory.."
+        $ENTCMD_PREFIX mkdir -p /tmp/.X11-unix || {
+            log "Error: Failed to create /tmp/.X11-unix directory"
+            exit 1
+        }
+        # Set required perms..
+        $ENTCMD_PREFIX chmod 1777 /tmp/.X11-unix || {
+            log "Error: Failed to chmod /tmp/.X11-unix to 1777"
+            exit 1
+        }
+    fi
+
+    # Handle user permissions
+    log "Ensuring user permissions..."
+    handle_user_permissions || exit 1
 
     # Setup namespaceless env if needed for container runtime
     if [[ "$container_runtime" != "podman" ]]; then
@@ -336,7 +350,7 @@ main() {
 
     # Make sure /run/udev/ directory exists with /run/udev/control, needed for virtual controller support
     if [[ ! -d "/run/udev" || ! -e "/run/udev/control" ]]; then
-        log "Creating /run/udev directory and control file..."
+        log "Creating /run/udev directory and control file.."
         $ENTCMD_PREFIX mkdir -p /run/udev || {
             log "Error: Failed to create /run/udev directory"
             exit 1