fix(hive-metric): use opentelemetry-otlp SDK instead of hand-rolled OTLP

hive-metric/Cargo.toml

@@ -10,6 +10,13 @@ path = "src/main.rs"
 [dependencies]
 anyhow.workspace = true
 clap.workspace = true
-reqwest.workspace = true
-serde_json.workspace = true
+# OTEL SDK — only used by this crate, so kept local rather than in workspace.dependencies.
+opentelemetry = "0.32"
+opentelemetry_sdk = { version = "0.32", features = ["metrics"] }
+opentelemetry-otlp = { version = "0.32", default-features = false, features = [
+  "metrics",
+  "http-json",
+  "reqwest-client",
+  "reqwest-rustls",
+] }
 tokio = { workspace = true, features = ["rt", "macros"] }