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/vbs_notification.rs

@@ -1,7 +1,7 @@
-use std::process::Command;
 use std::io::Write;
-use tempfile::NamedTempFile;
+use std::process::Command;
 use tauri::command;
+use tempfile::NamedTempFile;
 
 #[command]
 pub async fn send_vbs_notification(title: String, body: String) -> Result<(), String> {
@@ -17,8 +17,8 @@ objShell.Popup "{}" & vbCrLf & vbCrLf & "{}", 5, "{}", 64
     );
 
     // Create a temporary VBS file
-    let mut temp_file = NamedTempFile::new()
-        .map_err(|e| format!("Failed to create temp file: {}", e))?;
+    let mut temp_file =
+        NamedTempFile::new().map_err(|e| format!("Failed to create temp file: {}", e))?;
 
     temp_file
         .write_all(vbs_content.as_bytes())
@@ -40,10 +40,7 @@ objShell.Popup "{}" & vbCrLf & vbCrLf & "{}", 5, "{}", 64
     } else if temp_path.starts_with("/tmp/") {
         // WSL temp files might be in a different location
         // Try to use wslpath to convert
-        let output = Command::new("wslpath")
-            .arg("-w")
-            .arg(&temp_path)
-            .output();
+        let output = Command::new("wslpath").arg("-w").arg(&temp_path).output();
 
         if let Ok(result) = output {
             if result.status.success() {
@@ -71,4 +68,4 @@ objShell.Popup "{}" & vbCrLf & vbCrLf & "{}", 5, "{}", 64
     }
 
     Ok(())
-}
+}