signerproxy: Upgrade dependencies and remove async from entry points (Phase 3 & 4)

Phase 3 - Upgrade dependencies to modern versions:
- tokio: 0.2 -> 1.x with minimal features (rt, net, io-util only)
- tonic: 0.3 -> 0.8 (matches workspace)
- prost: 0.6 -> 0.11 (matches workspace)
- tonic-build: 0.3 -> 0.8 (matches workspace)
- tower: 0.3 -> 0.4 (matches workspace)

Phase 4 - Remove async from entry points:
- lib.rs: Remove async from Proxy::run()
- signerproxy.rs: Remove #[tokio::main] and async from main()

The subdaemon now uses only std threading with a minimal tokio
runtime exclusively for gRPC operations. No more old tokio 0.2
dependency and no async/await except where required by tonic.

Author: claude

libs/gl-signerproxy/Cargo.toml

@@ -15,16 +15,17 @@ name = "gl-signerproxy"
 path = "src/bin/signerproxy.rs"
 
 [build-dependencies]
-tonic-build = "0.3"
+tonic-build = "0.8"
 
 [dependencies]
 anyhow = { workspace = true }
 env_logger = { workspace = true }
-tokio = { version = "0.2", features = ["full"] }
-tonic = { version = "0.3", features = ["tls", "transport"] }
-prost = "0.6"
-log = "0.4"
-tower = "0.3"
+# Minimal tokio - only for gRPC client runtime
+tokio = { version = "1", features = ["rt", "net", "io-util"] }
+tonic = { version = "0.8", features = ["tls", "transport"] }
+prost = "0.11"
+log = "*"
+tower = "0.4"
 which = "4.4.2"
 libc = "0.2"
 byteorder = "1.5.0"

libs/gl-signerproxy/src/bin/signerproxy.rs

@@ -1,11 +1,10 @@
 use anyhow::Result;
 use gl_signerproxy::Proxy;
 
-#[tokio::main]
-async fn main() -> Result<()> {
+fn main() -> Result<()> {
     env_logger::builder()
         .target(env_logger::Target::Stderr)
         .init();
 
-    Proxy::new().run().await
+    Proxy::new().run()
 }

libs/gl-signerproxy/src/lib.rs

@@ -12,7 +12,7 @@ impl Proxy {
         Proxy {}
     }
 
-    pub async fn run(&self) -> Result<()> {
-        hsmproxy::run().await
+    pub fn run(&self) -> Result<()> {
+        hsmproxy::run()
     }
 }