feat: add Feishu/Lark WASM channel plugin (#1110)

part of #1046

  - Implement Feishu Event Subscription v2.0 webhook (URL verification + im.message.receive_v1)
  - Token exchange via workspace-cached app credentials with 5-min pre-expiry refresh
  - Host-side secret injection into config JSON (setup.rs) so WASM can access app_id/app_secret without env vars
  - Reply and broadcast via /open-apis/im/v1/messages
  - Enforce allow_from user filtering in message handler
  - DM pairing flow with owner_id restriction
  - Dual API base support: open.feishu.cn (Feishu) / open.larksuite.com (Lark)
  - Registry manifest, bundled channel entry, messaging bundle integration
  - Strip raw config_json debug log to prevent secret leakage

channels-src/feishu/Cargo.toml

@@ -0,0 +1,28 @@
+[package]
+name = "feishu-channel"
+version = "0.1.0"
+edition = "2021"
+description = "Feishu/Lark Bot channel for IronClaw"
+license = "MIT OR Apache-2.0"
+
+[lib]
+crate-type = ["cdylib"]
+
+[dependencies]
+# WIT bindgen for WASM component model
+wit-bindgen = "0.36"
+
+# Serialization
+serde = { version = "1.0", features = ["derive"] }
+serde_json = "1.0"
+
+# Exclude from parent workspace (this is a standalone WASM component)
+
+[profile.release]
+# Optimize for size
+opt-level = "s"
+lto = true
+strip = true
+codegen-units = 1
+
+[workspace]