feat: another wave of features (#61)

## Explanation

This PR bundles several user-facing improvements and feature additions for the v0.3.0 release, including quality-of-life improvements to the UI, new slash commands, better state persistence, and auto-update checking.

## Included Changes

- **Resizable chat input** with drag handle (#58 partial)
- **Arrow key navigation fix** - cursor keys now navigate text when user has typed input (#58)
- **Scroll position persistence** per conversation tab
- **/skill command** for invoking Claude Code skills (#57)
- **Stats persistence fix** - stats now persist across session changes, only reset on disconnect (#59)
- **Auto-update checker** on startup (#17)
- **Resizable character panel** with full-height sprites (#10)
- **Font size and zoom settings** with keyboard shortcuts (Ctrl++/Ctrl+-/Ctrl+0) (#19)

## Closes

Closes #10, #17, #19, #57, #58, #59

## Attestations

- [x] I have read and agree to the Code of Conduct
- [x] I have read and agree to the Community Guidelines
- [x] My contribution complies with the Contributor Covenant
- [x] I have run the linter and resolved any errors
- [x] My pull request uses an appropriate title, matching the conventional commit standards
- [x] My scope of feat/fix/chore/etc. correctly matches the nature of changes in my pull request
- [x] All new and existing tests pass locally with my changes
- [x] Code coverage remains at or above the configured threshold

## Documentation

N/A - Internal app features

## Versioning

Minor - My pull request introduces new non-breaking features.

---
✨ This PR was created with help from Hikari~ 🌸

Co-authored-by: Hikari <hikari@nhcarrigan.com>
Reviewed-on: #61
Co-authored-by: Naomi Carrigan <commits@nhcarrigan.com>
Co-committed-by: Naomi Carrigan <commits@nhcarrigan.com>

src-tauri/src/lib.rs

@@ -5,18 +5,18 @@ mod config;
 mod notifications;
 mod stats;
 mod types;
-mod wsl_bridge;
-mod wsl_notifications;
 mod vbs_notification;
 mod windows_toast;
+mod wsl_bridge;
+mod wsl_notifications;
 
-use commands::*;
-use notifications::*;
 use bridge_manager::create_shared_bridge_manager;
 use commands::load_saved_achievements;
-use wsl_notifications::*;
+use commands::*;
+use notifications::*;
 use vbs_notification::*;
 use windows_toast::*;
+use wsl_notifications::*;
 
 #[cfg_attr(mobile, tauri::mobile_entry_point)]
 pub fn run() {
@@ -29,6 +29,7 @@ pub fn run() {
         .plugin(tauri_plugin_store::Builder::new().build())
         .plugin(tauri_plugin_notification::init())
         .plugin(tauri_plugin_os::init())
+        .plugin(tauri_plugin_http::init())
         .manage(bridge_manager.clone())
         .setup(move |app| {
             // Initialize the app handle in the bridge manager
@@ -55,6 +56,8 @@ pub fn run() {
             send_wsl_notification,
             send_vbs_notification,
             validate_directory,
+            list_skills,
+            check_for_updates,
         ])
         .run(tauri::generate_context!())
         .expect("error while running tauri application");