Merge PDLB (Prefill-Decode Load Balancer) into SGLang Router (#7096)

sgl-router/Cargo.toml

@@ -15,7 +15,7 @@ serde = { version = "1.0", features = ["derive"] }
 clap = { version = "4.4", features = ["derive"] }
 bytes = "1.8.0"
 rand = "0.8.5"
-reqwest = { version = "0.12.8", features = ["stream", "blocking"] }
+reqwest = { version = "0.12.8", features = ["stream", "blocking", "json"] }
 futures-util = "0.3"
 serde_json = "1.0"
 pyo3 = { version = "0.22.5", features = ["extension-module"] }
@@ -33,6 +33,8 @@ futures = "0.3"
 # Added for metrics
 metrics = "0.24.2"
 metrics-exporter-prometheus = "0.17.0"
+# Added for request tracing
+uuid = { version = "1.10", features = ["v4", "serde"] }
 [profile.release]
 lto = "thin"
 codegen-units = 1