feat(event-notifier): improve environment variable handling

- Fix deserialization error when parsing config from environment variables
- Add proper array format support for adapters configuration
- Update environment variable examples with correct format
- Improve documentation for configuration loading
- Implement helper functions for environment variable validation

This change fixes the "invalid type: map, expected a sequence" error
by ensuring proper formatting of array-type fields in environment variables.

Cargo.lock

@@ -664,15 +664,6 @@ dependencies = [
  "num-traits",
 ]
 
-[[package]]
-name = "atomic"
-version = "0.6.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8d818003e740b63afc82337e3160717f4f63078720a810b7b903e70a5d1d2994"
-dependencies = [
- "bytemuck",
-]
-
 [[package]]
 name = "atomic-waker"
 version = "1.1.2"
@@ -1026,12 +1017,6 @@ version = "3.17.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1628fb46dfa0b37568d12e5edd512553eccf6a22a78e8bde00bb4aed84d5bdbf"
 
-[[package]]
-name = "bytemuck"
-version = "1.22.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b6b1fc10dbac614ebc03540c9dbd60e83887fda27794998c6528f1782047d540"
-
 [[package]]
 name = "byteorder"
 version = "1.5.0"
@@ -3034,12 +3019,6 @@ dependencies = [
  "const-random",
 ]
 
-[[package]]
-name = "dotenvy"
-version = "0.15.7"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1aaf95b3e5c8f23aa320147307562d361db0ae0d51242340f558153b4eb2439b"
-
 [[package]]
 name = "dpi"
 version = "0.1.1"
@@ -3288,21 +3267,6 @@ dependencies = [
  "rustc_version",
 ]
 
-[[package]]
-name = "figment"
-version = "0.10.19"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8cb01cd46b0cf372153850f4c6c272d9cbea2da513e07538405148f95bd789f3"
-dependencies = [
- "atomic",
- "pear",
- "serde",
- "serde_yaml",
- "toml",
- "uncased",
- "version_check",
-]
-
 [[package]]
 name = "fixedbitset"
 version = "0.5.7"
@@ -4435,12 +4399,6 @@ dependencies = [
  "cfb",
 ]
 
-[[package]]
-name = "inlinable_string"
-version = "0.1.15"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c8fae54786f62fb2918dcfae3d568594e50eb9b5c25bf04371af6fe7516452fb"
-
 [[package]]
 name = "inout"
 version = "0.1.4"
@@ -6048,29 +6006,6 @@ dependencies = [
  "hmac 0.12.1",
 ]
 
-[[package]]
-name = "pear"
-version = "0.2.9"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bdeeaa00ce488657faba8ebf44ab9361f9365a97bd39ffb8a60663f57ff4b467"
-dependencies = [
- "inlinable_string",
- "pear_codegen",
- "yansi",
-]
-
-[[package]]
-name = "pear_codegen"
-version = "0.2.9"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4bab5b985dc082b345f812b7df84e1bef27e7207b39e448439ba8bd69c93f147"
-dependencies = [
- "proc-macro2",
- "proc-macro2-diagnostics",
- "quote",
- "syn 2.0.100",
-]
-
 [[package]]
 name = "pem"
 version = "3.0.5"
@@ -6549,7 +6484,6 @@ dependencies = [
  "quote",
  "syn 2.0.100",
  "version_check",
- "yansi",
 ]
 
 [[package]]
@@ -7351,8 +7285,7 @@ version = "0.0.1"
 dependencies = [
  "async-trait",
  "axum",
- "dotenvy",
- "figment",
+ "config",
  "http",
  "rdkafka",
  "reqwest",
@@ -7832,19 +7765,6 @@ dependencies = [
  "syn 2.0.100",
 ]
 
-[[package]]
-name = "serde_yaml"
-version = "0.9.34+deprecated"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6a8b1a1a2ebf674015cc02edccce75287f1a0130d394307b36743c2f5d504b47"
-dependencies = [
- "indexmap 2.9.0",
- "itoa 1.0.15",
- "ryu",
- "serde",
- "unsafe-libyaml",
-]
-
 [[package]]
 name = "server_fn"
 version = "0.6.15"
@@ -9175,15 +9095,6 @@ dependencies = [
  "winapi",
 ]
 
-[[package]]
-name = "uncased"
-version = "0.9.10"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e1b88fcfe09e89d3866a5c11019378088af2d24c3fbd4f0543f96b479ec90697"
-dependencies = [
- "version_check",
-]
-
 [[package]]
 name = "unicase"
 version = "2.8.1"
@@ -9224,12 +9135,6 @@ dependencies = [
  "subtle",
 ]
 
-[[package]]
-name = "unsafe-libyaml"
-version = "0.2.11"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "673aac59facbab8a9007c7f6108d11f63b603f7cabff99fabf650fea5c32b861"
-
 [[package]]
 name = "untrusted"
 version = "0.9.0"
@@ -10223,12 +10128,6 @@ dependencies = [
  "hashlink",
 ]
 
-[[package]]
-name = "yansi"
-version = "1.0.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cfe53a6657fd280eaa890a3bc59152892ffa3e30101319d168b781ed6529b049"
-
 [[package]]
 name = "yoke"
 version = "0.7.5"