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/bridge_manager.rs

@@ -29,30 +29,40 @@ impl BridgeManager {
         conversation_id: &str,
         options: ClaudeStartOptions,
     ) -> Result<(), String> {
-        // Check if a bridge already exists for this conversation
-        if self.bridges.get(conversation_id).map(|b| b.is_running()).unwrap_or(false) {
+        // Check if a bridge already exists and is running for this conversation
+        if self
+            .bridges
+            .get(conversation_id)
+            .map(|b| b.is_running())
+            .unwrap_or(false)
+        {
             return Err("Claude is already running for this conversation".to_string());
         }
 
-        let app = self.app_handle.as_ref()
+        let app = self
+            .app_handle
+            .as_ref()
             .ok_or_else(|| "App handle not set".to_string())?
             .clone();
 
-        // Create a new bridge for this conversation
-        let mut bridge = WslBridge::new_with_conversation_id(conversation_id.to_string());
+        // Reuse existing bridge if it exists (preserves stats across reconnects)
+        // Only create a new bridge if one doesn't exist for this conversation
+        let bridge = self
+            .bridges
+            .entry(conversation_id.to_string())
+            .or_insert_with(|| WslBridge::new_with_conversation_id(conversation_id.to_string()));
 
         // Start the Claude process
         bridge.start(app, options)?;
 
-        // Store the bridge
-        self.bridges.insert(conversation_id.to_string(), bridge);
-
         Ok(())
     }
 
     pub fn stop_claude(&mut self, conversation_id: &str) -> Result<(), String> {
         if let Some(bridge) = self.bridges.get_mut(conversation_id) {
-            let app = self.app_handle.as_ref()
+            let app = self
+                .app_handle
+                .as_ref()
                 .ok_or_else(|| "App handle not set".to_string())?;
             bridge.stop(app);
             Ok(())
@@ -63,7 +73,9 @@ impl BridgeManager {
 
     pub fn interrupt_claude(&mut self, conversation_id: &str) -> Result<(), String> {
         if let Some(bridge) = self.bridges.get_mut(conversation_id) {
-            let app = self.app_handle.as_ref()
+            let app = self
+                .app_handle
+                .as_ref()
                 .ok_or_else(|| "App handle not set".to_string())?;
             bridge.interrupt(app)
         } else {
@@ -79,7 +91,12 @@ impl BridgeManager {
         }
     }
 
-    pub fn send_tool_result(&mut self, conversation_id: &str, tool_use_id: &str, result: serde_json::Value) -> Result<(), String> {
+    pub fn send_tool_result(
+        &mut self,
+        conversation_id: &str,
+        tool_use_id: &str,
+        result: serde_json::Value,
+    ) -> Result<(), String> {
         if let Some(bridge) = self.bridges.get_mut(conversation_id) {
             bridge.send_tool_result(tool_use_id, result)
         } else {
@@ -88,19 +105,22 @@ impl BridgeManager {
     }
 
     pub fn is_claude_running(&self, conversation_id: &str) -> bool {
-        self.bridges.get(conversation_id)
+        self.bridges
+            .get(conversation_id)
             .map(|b| b.is_running())
             .unwrap_or(false)
     }
 
     pub fn get_working_directory(&self, conversation_id: &str) -> Result<String, String> {
-        self.bridges.get(conversation_id)
+        self.bridges
+            .get(conversation_id)
             .map(|b| b.get_working_directory().to_string())
             .ok_or_else(|| "No Claude instance found for this conversation".to_string())
     }
 
     pub fn get_usage_stats(&self, conversation_id: &str) -> Result<UsageStats, String> {
-        self.bridges.get(conversation_id)
+        self.bridges
+            .get(conversation_id)
             .map(|b| b.get_stats())
             .ok_or_else(|| "No Claude instance found for this conversation".to_string())
     }
@@ -123,8 +143,14 @@ impl BridgeManager {
 
     #[allow(dead_code)]
     pub fn get_active_conversations(&self) -> Vec<String> {
-        self.bridges.keys()
-            .filter(|id| self.bridges.get(*id).map(|b| b.is_running()).unwrap_or(false))
+        self.bridges
+            .keys()
+            .filter(|id| {
+                self.bridges
+                    .get(*id)
+                    .map(|b| b.is_running())
+                    .unwrap_or(false)
+            })
             .cloned()
             .collect()
     }
@@ -140,4 +166,4 @@ pub type SharedBridgeManager = Arc<Mutex<BridgeManager>>;
 
 pub fn create_shared_bridge_manager() -> SharedBridgeManager {
     Arc::new(Mutex::new(BridgeManager::new()))
-}
+}