feat(easytier): instrument hot-path locks, channels, and functions

Wrap the per-packet locks and channels behind hotpath's drop-in wrappers
() so lock contention and
channel flow become visible when the  feature is on, while staying
zero-cost in default builds via cfg-gated dual imports and the no-op
// macros. Annotate the hottest send/recv,
encrypt/decrypt, and forward functions with .

Coverage: peer_conn/peer_manager/peer_map/peer/peer_session/secure_datagram
locks, mpsc/ring/udp/wireguard/fake_tcp channels, quic connection pool,
relay/foreign send paths, and OSPF route lookup (function-level only; its
parking_lot upgradable guards have no hotpath wrapper).

Debug impls that formatted lock fields are updated to dereference the inner
value, and quic's RwPool switches to a manual Debug that skips the locks.

Cargo.lock

@@ -263,6 +263,12 @@ version = "0.7.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7c02d123df017efcdfbd739ef81735b36c5ba83ec3c59c80a9d7ecc718f92e50"
 
+[[package]]
+name = "ascii"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d92bec98840b8f03a5ff5413de5293bfcd8bf96467cf5452609f939ec6f5de16"
+
 [[package]]
 name = "async-broadcast"
 version = "0.7.2"
@@ -1260,6 +1266,12 @@ dependencies = [
  "windows-targets 0.52.6",
 ]
 
+[[package]]
+name = "chunked_transfer"
+version = "1.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6e4de3bc4ea267985becf712dc6d9eed8b04c953b3fcfb339ebc87acd9804901"
+
 [[package]]
 name = "ciborium"
 version = "0.2.2"
@@ -2163,6 +2175,16 @@ dependencies = [
  "dirs-sys 0.5.0",
 ]
 
+[[package]]
+name = "dirs-next"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b98cf8ebf19c3d1b223e151f99a4f9f0690dca41414773390fc824184ac833e1"
+dependencies = [
+ "cfg-if",
+ "dirs-sys-next",
+]
+
 [[package]]
 name = "dirs-sys"
 version = "0.3.7"
@@ -2186,6 +2208,17 @@ dependencies = [
  "windows-sys 0.61.2",
 ]
 
+[[package]]
+name = "dirs-sys-next"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4ebda144c4fe02d1f7ea1a7d9641b6fc6b580adcfa024ae48797ecdeb6825b4d"
+dependencies = [
+ "libc",
+ "redox_users 0.4.5",
+ "winapi",
+]
+
 [[package]]
 name = "dispatch2"
 version = "0.3.1"
@@ -2365,6 +2398,7 @@ dependencies = [
  "hickory-resolver",
  "hickory-server",
  "hmac",
+ "hotpath",
  "http",
  "http_req",
  "humansize",
@@ -2707,6 +2741,12 @@ version = "1.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4ef6b89e5b37196644d8796de5268852ff179b44e96276cf4290264843743bb7"
 
+[[package]]
+name = "encode_unicode"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "34aa73646ffb006b8f5147f3dc182bd4bcb190227ce861fc4a4844bf8e3cb2c0"
+
 [[package]]
 name = "encoding"
 version = "0.2.33"
@@ -3965,6 +4005,61 @@ dependencies = [
  "windows-sys 0.52.0",
 ]
 
+[[package]]
+name = "hotpath"
+version = "0.19.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "467479f30ae7262ad93eff1f6653a58ecfca4b44dd9ff82ef4b469ba1ad00017"
+dependencies = [
+ "arc-swap",
+ "cfg-if",
+ "crossbeam-channel",
+ "flate2",
+ "flume 0.12.0",
+ "futures-util",
+ "hdrhistogram",
+ "hotpath-macros",
+ "hotpath-meta",
+ "libc",
+ "object",
+ "parking_lot",
+ "pin-project-lite",
+ "prettytable-rs",
+ "quanta",
+ "regex",
+ "rustc-demangle",
+ "serde",
+ "serde_json",
+ "tiny_http",
+ "tokio",
+]
+
+[[package]]
+name = "hotpath-macros"
+version = "0.19.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7edb8da2a00454786fbb75ab24c4f72380afeb9b5136776caa7737df9895bfa7"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.117",
+]
+
+[[package]]
+name = "hotpath-macros-meta"
+version = "0.19.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e804ccbbd13922ff16b752ab72043d15ea38411a03a82917b8ea5b36b6b45655"
+
+[[package]]
+name = "hotpath-meta"
+version = "0.19.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7f76b1b9a176e5677878243b0c9052d2e0a62405359bd6990bbd85b59cafa2aa"
+dependencies = [
+ "hotpath-macros-meta",
+]
+
 [[package]]
 name = "html5ever"
 version = "0.29.1"
@@ -5933,6 +6028,15 @@ dependencies = [
  "objc2-foundation",
 ]
 
+[[package]]
+name = "object"
+version = "0.36.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "62948e14d923ea95ea2c7c86c71013138b66525b86bdc08d2dcc262bdb497b87"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "once_cell"
 version = "1.21.3"
@@ -6837,6 +6941,19 @@ dependencies = [
  "syn 2.0.117",
 ]
 
+[[package]]
+name = "prettytable-rs"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "eea25e07510aa6ab6547308ebe3c036016d162b8da920dbb079e3ba8acf3d95a"
+dependencies = [
+ "encode_unicode",
+ "is-terminal",
+ "lazy_static",
+ "term",
+ "unicode-width 0.1.11",
+]
+
 [[package]]
 name = "primeorder"
 version = "0.13.6"
@@ -7896,6 +8013,12 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "rustc-demangle"
+version = "0.1.27"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b50b8869d9fc858ce7266cce0194bd74df58b9d0e3f6df3a9fc8eb470d95c09d"
+
 [[package]]
 name = "rustc-hash"
 version = "2.1.0"
@@ -9820,6 +9943,17 @@ dependencies = [
  "utf-8",
 ]
 
+[[package]]
+name = "term"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c59df8ac95d96ff9bede18eb7300b0fda5e5d8d90960e76f8e14ae765eedbf1f"
+dependencies = [
+ "dirs-next",
+ "rustversion",
+ "winapi",
+]
+
 [[package]]
 name = "terminal_size"
 version = "0.4.1"
@@ -9975,6 +10109,18 @@ version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "825f6c8a18bc36d56a62f66af7296385b628c9c5543a8663d4c217fc920bfefd"
 
+[[package]]
+name = "tiny_http"
+version = "0.12.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "389915df6413a2e74fb181895f933386023c71110878cd0825588928e64cdc82"
+dependencies = [
+ "ascii",
+ "chunked_transfer",
+ "httpdate",
+ "log",
+]
+
 [[package]]
 name = "tinystr"
 version = "0.7.6"