fix(deps): 升级 wechatbot 的 reqwest 至 0.13，消除版本冲突

主 crate 用 reqwest 0.13.2，而 vendored wechatbot 仍用 0.12，
导致 Cargo 同时编译两套 reqwest 及其传递依赖，拖慢编译、增大二进制。

改动：
- vendor/wechatbot/Cargo.toml: reqwest 0.12 -> 0.13，feature rustls-tls -> rustls
  （reqwest 0.13 移除了 rustls-tls feature，改为细粒度的 rustls）
- Cargo.lock: 合并两份 reqwest 为一份 0.13.3，移除 0.12.28 条目

wechatbot 对 reqwest 的使用仅限稳定客户端 API（Client::builder、
get/post/json/body/send、status/text/bytes/headers），0.12 -> 0.13 无破坏性变更，
源码零改动。

验证：
- cargo check 通过
- cargo test --no-run 全部测试二进制编译通过
- cargo test --lib: 494 passed，3 个失败经 stash 对照确认为预存技术债

Cargo.lock

@@ -1028,7 +1028,6 @@ dependencies = [
  "tokio",
  "tokio-rustls",
  "tower-service",
- "webpki-roots 1.0.7",
 ]
 
 [[package]]
@@ -1661,7 +1660,7 @@ dependencies = [
  "r2d2",
  "r2d2_sqlite",
  "regex",
- "reqwest 0.13.3",
+ "reqwest",
  "rmcp",
  "rusqlite",
  "rust-embed",
@@ -2026,44 +2025,6 @@ version = "0.8.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "dc897dd8d9e8bd1ed8cdad82b5966c3e0ecae09fb1907d58efaa013543185d0a"
 
-[[package]]
-name = "reqwest"
-version = "0.12.28"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "eddd3ca559203180a307f12d114c268abf583f59b03cb906fd0b3ff8646c1147"
-dependencies = [
- "base64",
- "bytes",
- "futures-core",
- "http",
- "http-body",
- "http-body-util",
- "hyper",
- "hyper-rustls",
- "hyper-util",
- "js-sys",
- "log",
- "percent-encoding",
- "pin-project-lite",
- "quinn",
- "rustls",
- "rustls-pki-types",
- "serde",
- "serde_json",
- "serde_urlencoded",
- "sync_wrapper",
- "tokio",
- "tokio-rustls",
- "tower",
- "tower-http",
- "tower-service",
- "url",
- "wasm-bindgen",
- "wasm-bindgen-futures",
- "web-sys",
- "webpki-roots 1.0.7",
-]
-
 [[package]]
 name = "reqwest"
 version = "0.13.3"
@@ -2133,7 +2094,7 @@ dependencies = [
  "pastey",
  "pin-project-lite",
  "process-wrap",
- "reqwest 0.13.3",
+ "reqwest",
  "rmcp-macros",
  "schemars",
  "serde",
@@ -3363,7 +3324,7 @@ dependencies = [
  "hex",
  "md-5",
  "rand 0.10.1",
- "reqwest 0.12.28",
+ "reqwest",
  "serde",
  "serde_json",
  "serde_repr",

vendor/wechatbot/Cargo.toml

@@ -53,9 +53,9 @@ version = "0.10"
 version = "0.10"
 
 [dependencies.reqwest]
-version = "0.12"
+version = "0.13"
 default-features = false
-features = ["json", "rustls-tls"]
+features = ["json", "rustls"]
 
 [dependencies.serde]
 version = "1"