feat: add optional hotpath profiling support (#2380)

* feat: add hotpath profiling support
* perf(hotpath): make hotpath an optional dependency

easytier/Cargo.toml

@@ -52,6 +52,7 @@ toml = "0.8.12"
 chrono = { version = "0.4.37", features = ["serde"] }
 
 guarden = "0.2"
+hotpath = { version = "0.18", default-features = false, optional = true }
 
 delegate = "0.13.5"
 
@@ -401,6 +402,15 @@ jemalloc-prof = [
     "jemalloc-sys/stats",
 ]
 tracing = ["tokio/tracing", "dep:console-subscriber"]
+hotpath = [
+    "dep:hotpath",
+    "hotpath/hotpath",
+    "hotpath/tokio",
+    "hotpath/parking_lot",
+    "hotpath/flume",
+]
+hotpath-cpu = ["hotpath", "hotpath/hotpath-cpu"]
+hotpath-alloc = ["hotpath", "hotpath/hotpath-alloc"]
 magic-dns = ["dep:hickory-client", "dep:hickory-server"]
 faketcp = ["dep:flume"]
 zstd = ["dep:zstd"]