feat: add session import/export functionality

- Add JSON export with full session metadata for backup/restore
- Add Markdown export with formatted conversation history
- Add import capability for previously exported sessions
- Add tauri-plugin-fs for file system operations
- Add export dropdown menu and import button to session history panel

src-tauri/Cargo.lock

@@ -1613,6 +1613,7 @@ dependencies = [
  "tauri-build",
  "tauri-plugin-clipboard-manager",
  "tauri-plugin-dialog",
+ "tauri-plugin-fs",
  "tauri-plugin-http",
  "tauri-plugin-notification",
  "tauri-plugin-opener",

src-tauri/Cargo.toml

@@ -27,6 +27,7 @@ tauri-plugin-notification = "2"
 tauri-plugin-os = "2"
 tauri-plugin-http = "2"
 tauri-plugin-clipboard-manager = "2"
+tauri-plugin-fs = "2"
 tempfile = "3"
 semver = "1"
 chrono = { version = "0.4.43", features = ["serde"] }

src-tauri/capabilities/default.json

@@ -16,6 +16,9 @@
     "notification:allow-notify",
     "clipboard-manager:default",
     "clipboard-manager:allow-read-image",
-    "core:tray:default"
+    "core:tray:default",
+    "fs:default",
+    "fs:allow-read-text-file",
+    "fs:allow-write-text-file"
   ]
 }

src-tauri/src/lib.rs

@@ -39,6 +39,7 @@ pub fn run() {
         .plugin(tauri_plugin_os::init())
         .plugin(tauri_plugin_http::init())
         .plugin(tauri_plugin_clipboard_manager::init())
+        .plugin(tauri_plugin_fs::init())
         .manage(bridge_manager.clone())
         .manage(temp_manager.clone())
         .setup(move |app| {