perf(cortex-gui): optimize Tauri app with async patterns and reduced dependencies

- Remove blocking reqwest feature in favor of async-only HTTP client
- Remove unused direct dependencies: wry and plist (provided by tauri)
- Remove blocking HttpTransport in favor of AsyncHttpTransport
- Update Cargo.lock with reduced dependencies

Key optimizations:
- Prevents sync blocking in async Tauri command context
- Smaller binary size due to fewer dependencies
- Cleaner async/await patterns for HTTP communication

The frontend already uses VirtualList for large lists (FileExplorer,
SearchSidebar, MessageList) which is optimal for SolidJS.

Author: factorydroid

Cargo.lock

@@ -59,7 +59,8 @@ dirs = "5"
 parking_lot = "0.12"
 sysinfo = { version = "0.32", default-features = false, features = ["system"] }
 chrono = { version = "0.4", features = ["serde"] }
-reqwest = { version = "0.12", features = ["json", "blocking", "stream"] }
+# Async-only HTTP client - blocking feature removed to prevent sync blocking in async context
+reqwest = { version = "0.12", features = ["json", "stream"] }
 glob = "0.3"
 walkdir = "2"
 regex = "1"
@@ -102,10 +103,7 @@ libc = "0.2"
 interprocess = { version = "2.2", features = ["tokio"] }
 enigo = "0.3"
 image = "0.24"
-plist = "1.6"
-
-# Webview
-wry = "0.53"
+# Note: plist and wry are provided by tauri and don't need direct dependencies
 
 # Security - credential encryption
 keyring = { version = "3", default-features = false, features = ["windows-native", "apple-native", "linux-native"] }