node: use git hash for user agent

Cargo.lock

@@ -1314,6 +1314,9 @@ name = "built"
 version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f4ad8f11f288f48ca24471bbd51ac257aaeaaa07adae295591266b792902ae64"
+dependencies = [
+ "git2",
+]
 
 [[package]]
 name = "bumpalo"
@@ -3693,6 +3696,19 @@ version = "0.32.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e629b9b98ef3dd8afe6ca2bd0f89306cec16d43d907889945bc5d6687f2f13c7"
 
+[[package]]
+name = "git2"
+version = "0.20.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7b88256088d75a56f8ecfa070513a775dd9107f6530ef14919dac831af9cfe2b"
+dependencies = [
+ "bitflags 2.10.0",
+ "libc",
+ "libgit2-sys",
+ "log",
+ "url",
+]
+
 [[package]]
 name = "gl_generator"
 version = "0.14.0"
@@ -4095,6 +4111,7 @@ name = "grin_p2p"
 version = "5.4.0"
 dependencies = [
  "bitflags 1.3.2",
+ "built",
  "bytes 0.5.6",
  "chrono",
  "enum_primitive",
@@ -5607,6 +5624,18 @@ dependencies = [
  "cc",
 ]
 
+[[package]]
+name = "libgit2-sys"
+version = "0.18.3+1.9.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c9b3acc4b91781bb0b3386669d325163746af5f6e4f73e6d2d630e09a35f3487"
+dependencies = [
+ "cc",
+ "libc",
+ "libz-sys",
+ "pkg-config",
+]
+
 [[package]]
 name = "libloading"
 version = "0.8.9"
@@ -5665,6 +5694,18 @@ dependencies = [
  "vcpkg",
 ]
 
+[[package]]
+name = "libz-sys"
+version = "1.1.28"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fc3a226e576f50782b3305c5ccf458698f92798987f551c6a02efe8276721e22"
+dependencies = [
+ "cc",
+ "libc",
+ "pkg-config",
+ "vcpkg",
+]
+
 [[package]]
 name = "linked-hash-map"
 version = "0.5.6"