feat(server): 可观测性 Phase 1 — 健康检查路由 + Prometheus 指标 + 连接池/事件积压监控

- 添加 /health/live 存活探针别名（原 /health + /health/ready 保留）
- 新增 metrics middleware：http_requests_total 计数器 + http_request_duration_seconds 直方图
- Prometheus exporter 独立端口 9090（可通过 ERP__SERVER__METRICS_PORT 覆盖）
- 后台任务每 30s 采样 DB 连接池活跃/空闲连接数（pg_stat_activity）
- 后台任务每 30s 采样 EventBus pending 事件积压数
- UUID 路径归一化避免高基数（/api/v1/users/:id/posts）

Cargo.lock

@@ -288,6 +288,28 @@ version = "1.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c08606f8c3cbf4ce6ec8e28fb0014a2c086708fe954eaa885384a6165172e7e8"
 
+[[package]]
+name = "aws-lc-rs"
+version = "1.16.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0ec6fb3fe69024a75fa7e1bfb48aa6cf59706a101658ea01bfd33b2b248a038f"
+dependencies = [
+ "aws-lc-sys",
+ "zeroize",
+]
+
+[[package]]
+name = "aws-lc-sys"
+version = "0.40.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f50037ee5e1e41e7b8f9d161680a725bd1626cb6f8c7e901f91f942850852fe7"
+dependencies = [
+ "cc",
+ "cmake",
+ "dunce",
+ "fs_extra",
+]
+
 [[package]]
 name = "axum"
 version = "0.8.8"
@@ -555,7 +577,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d8144c22e24bbcf26ade86cb6501a0916c46b7e4787abdb0045a467eb1645a1d"
 dependencies = [
  "ambient-authority",
- "rand",
+ "rand 0.8.5",
 ]
 
 [[package]]
@@ -681,6 +703,15 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c8d4a3bb8b1e0c1050499d1815f5ab16d04f0959b233085fb31653fbfc9d98f9"
 
+[[package]]
+name = "cmake"
+version = "0.1.58"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c0f78a02292a74a88ac736019ab962ece0bc380e3f977bf72e376c5d78ff0678"
+dependencies = [
+ "cc",
+]
+
 [[package]]
 name = "cobs"
 version = "0.3.0"
@@ -1056,7 +1087,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "78c8292055d1c1df0cce5d180393dc8cce0abec0a7102adb6c7b1eef6016d60a"
 dependencies = [
  "generic-array",
- "rand_core",
+ "rand_core 0.6.4",
  "typenum",
 ]
 
@@ -1330,6 +1361,12 @@ dependencies = [
  "dtoa",
 ]
 
+[[package]]
+name = "dunce"
+version = "1.0.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "92773504d58c093f6de2459af4af33faa518c13451eb8f2b5698ed3d36e7c813"
+
 [[package]]
 name = "either"
 version = "1.15.0"
@@ -1453,7 +1490,7 @@ dependencies = [
  "dashmap",
  "hex",
  "hmac",
- "rand",
+ "rand 0.8.5",
  "sea-orm",
  "serde",
  "serde_json",
@@ -1663,6 +1700,8 @@ dependencies = [
  "erp-points",
  "erp-server-migration",
  "erp-workflow",
+ "metrics",
+ "metrics-exporter-prometheus",
  "moka",
  "redis",
  "sea-orm",
@@ -1842,6 +1881,12 @@ dependencies = [
  "windows-sys 0.52.0",
 ]
 
+[[package]]
+name = "fs_extra"
+version = "1.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "42703706b716c37f96a77aea830392ad231f44c9e9a67872fa5548707e11b11c"
+
 [[package]]
 name = "funty"
 version = "2.0.0"
@@ -2286,6 +2331,7 @@ dependencies = [
  "hyper",
  "hyper-util",
  "rustls",
+ "rustls-native-certs",
  "tokio",
  "tokio-rustls",
  "tower-service",
@@ -2478,8 +2524,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "af1955a75fa080c677d3972822ec4bad316169ab1cfc6c257a942c2265dbe5fe"
 dependencies = [
  "bitmaps",
- "rand_core",
- "rand_xoshiro",
+ "rand_core 0.6.4",
+ "rand_xoshiro 0.6.0",
  "sized-chunks",
  "typenum",
  "version_check",
@@ -2856,6 +2902,53 @@ dependencies = [
  "autocfg",
 ]
 
+[[package]]
+name = "metrics"
+version = "0.24.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5d5312e9ba3771cfa961b585728215e3d972c950a3eed9252aa093d6301277e8"
+dependencies = [
+ "ahash 0.8.12",
+ "portable-atomic",
+]
+
+[[package]]
+name = "metrics-exporter-prometheus"
+version = "0.16.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dd7399781913e5393588a8d8c6a2867bf85fb38eaf2502fdce465aad2dc6f034"
+dependencies = [
+ "base64 0.22.1",
+ "http-body-util",
+ "hyper",
+ "hyper-rustls",
+ "hyper-util",
+ "indexmap",
+ "ipnet",
+ "metrics",
+ "metrics-util",
+ "quanta",
+ "thiserror 1.0.69",
+ "tokio",
+ "tracing",
+]
+
+[[package]]
+name = "metrics-util"
+version = "0.19.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b8496cc523d1f94c1385dd8f0f0c2c480b2b8aeccb5b7e4485ad6365523ae376"
+dependencies = [
+ "crossbeam-epoch",
+ "crossbeam-utils",
+ "hashbrown 0.15.5",
+ "metrics",
+ "quanta",
+ "rand 0.9.4",
+ "rand_xoshiro 0.7.0",
+ "sketches-ddsketch",
+]
+
 [[package]]
 name = "mime"
 version = "0.3.17"
@@ -3009,7 +3102,7 @@ dependencies = [
  "num-integer",
  "num-iter",
  "num-traits",
- "rand",
+ "rand 0.8.5",
  "smallvec",
  "zeroize",
 ]
@@ -3218,7 +3311,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "346f04948ba92c43e8469c1ee6736c7563d71012b17d40745260fe106aac2166"
 dependencies = [
  "base64ct",
- "rand_core",
+ "rand_core 0.6.4",
  "subtle",
 ]
 
@@ -3342,7 +3435,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3c80231409c20246a13fddb31776fb942c38553c51e871f8cbd687a4cfb5843d"
 dependencies = [
  "phf_shared",
- "rand",
+ "rand 0.8.5",
 ]
 
 [[package]]
@@ -3572,6 +3665,21 @@ dependencies = [
  "syn 2.0.117",
 ]
 
+[[package]]
+name = "quanta"
+version = "0.12.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f3ab5a9d756f0d97bdc89019bd2e4ea098cf9cde50ee7564dde6b81ccc8f06c7"
+dependencies = [
+ "crossbeam-utils",
+ "libc",
+ "once_cell",
+ "raw-cpuid",
+ "wasi",
+ "web-sys",
+ "winapi",
+]
+
 [[package]]
 name = "quote"
 version = "1.0.45"
@@ -3606,8 +3714,18 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "34af8d1a0e25924bc5b7c43c079c942339d8f0a8b57c39049bef581b46327404"
 dependencies = [
  "libc",
- "rand_chacha",
- "rand_core",
+ "rand_chacha 0.3.1",
+ "rand_core 0.6.4",
+]
+
+[[package]]
+name = "rand"
+version = "0.9.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "44c5af06bb1b7d3216d91932aed5265164bf384dc89cd6ba05cf59a35f5f76ea"
+dependencies = [
+ "rand_chacha 0.9.0",
+ "rand_core 0.9.5",
 ]
 
 [[package]]
@@ -3617,7 +3735,17 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e6c10a63a0fa32252be49d21e7709d4d4baf8d231c2dbce1eaa8141b9b127d88"
 dependencies = [
  "ppv-lite86",
- "rand_core",
+ "rand_core 0.6.4",
+]
+
+[[package]]
+name = "rand_chacha"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d3022b5f1df60f26e1ffddd6c66e8aa15de382ae63b3a0c1bfc0e4d3e3f325cb"
+dependencies = [
+ "ppv-lite86",
+ "rand_core 0.9.5",
 ]
 
 [[package]]
@@ -3629,13 +3757,40 @@ dependencies = [
  "getrandom 0.2.17",
 ]
 
+[[package]]
+name = "rand_core"
+version = "0.9.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "76afc826de14238e6e8c374ddcc1fa19e374fd8dd986b0d2af0d02377261d83c"
+dependencies = [
+ "getrandom 0.3.4",
+]
+
 [[package]]
 name = "rand_xoshiro"
 version = "0.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6f97cdb2a36ed4183de61b2f824cc45c9f1037f28afe0a322e9fff4c108b5aaa"
 dependencies = [
- "rand_core",
+ "rand_core 0.6.4",
+]
+
+[[package]]
+name = "rand_xoshiro"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f703f4665700daf5512dcca5f43afa6af89f09db47fb56be587f80636bda2d41"
+dependencies = [
+ "rand_core 0.9.5",
+]
+
+[[package]]
+name = "raw-cpuid"
+version = "11.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "498cd0dc59d73224351ee52a95fee0f1a617a2eae0e7d9d720cc622c73a54186"
+dependencies = [
+ "bitflags",
 ]
 
 [[package]]
@@ -3876,7 +4031,7 @@ dependencies = [
  "num-traits",
  "pkcs1",
  "pkcs8",
- "rand_core",
+ "rand_core 0.6.4",
  "signature",
  "spki",
  "subtle",
@@ -3903,7 +4058,7 @@ dependencies = [
  "borsh",
  "bytes",
  "num-traits",
- "rand",
+ "rand 0.8.5",
  "rkyv",
  "serde",
  "serde_json",
@@ -3982,6 +4137,7 @@ version = "0.23.37"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "758025cb5fccfd3bc2fd74708fd4682be41d99e5dff73c377c0646c6012c73a4"
 dependencies = [
+ "aws-lc-rs",
  "once_cell",
  "ring",
  "rustls-pki-types",
@@ -3990,6 +4146,18 @@ dependencies = [
  "zeroize",
 ]
 
+[[package]]
+name = "rustls-native-certs"
+version = "0.8.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "612460d5f7bea540c490b2b6395d8e34a953e52b491accd6c86c8164c5932a63"
+dependencies = [
+ "openssl-probe",
+ "rustls-pki-types",
+ "schannel",
+ "security-framework",
+]
+
 [[package]]
 name = "rustls-pki-types"
 version = "1.14.0"
@@ -4005,6 +4173,7 @@ version = "0.103.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "20a6af516fea4b20eccceaf166e8aa666ac996208e8a644ce3ef5aa783bc7cd4"
 dependencies = [
+ "aws-lc-rs",
  "ring",
  "rustls-pki-types",
  "untrusted",
@@ -4398,7 +4567,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "77549399552de45a898a580c1b41d445bf730df867cc44e6c0233bbc4b8329de"
 dependencies = [
  "digest",
- "rand_core",
+ "rand_core 0.6.4",
 ]
 
 [[package]]
@@ -4441,6 +4610,12 @@ dependencies = [
  "typenum",
 ]
 
+[[package]]
+name = "sketches-ddsketch"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0c6f73aeb92d671e0cc4dca167e59b2deb6387c375391bc99ee743f326994a2b"
+
 [[package]]
 name = "slab"
 version = "0.4.12"
@@ -4618,7 +4793,7 @@ dependencies = [
  "memchr",
  "once_cell",
  "percent-encoding",
- "rand",
+ "rand 0.8.5",
  "rsa",
  "rust_decimal",
  "serde",
@@ -4662,7 +4837,7 @@ dependencies = [
  "memchr",
  "num-bigint",
  "once_cell",
- "rand",
+ "rand 0.8.5",
  "rust_decimal",
  "serde",
  "serde_json",