feat: add font size and zoom settings

- Add font_size config field (10-24px, default 14px)
- Add keyboard shortcuts: Ctrl++/- to adjust, Ctrl+0 to reset
- Add font size slider in Settings > Appearance
- Apply font size to Terminal and InputBar via CSS variable
- Persist font size preference between sessions

Closes #19

src-tauri/src/commands.rs

@@ -1,11 +1,11 @@
 use tauri::{AppHandle, State};
-use tauri_plugin_store::StoreExt;
 use tauri_plugin_http::reqwest;
+use tauri_plugin_store::StoreExt;
 
+use crate::achievements::{get_achievement_info, load_achievements, AchievementUnlockedEvent};
+use crate::bridge_manager::SharedBridgeManager;
 use crate::config::{ClaudeStartOptions, HikariConfig};
 use crate::stats::UsageStats;
-use crate::bridge_manager::SharedBridgeManager;
-use crate::achievements::{load_achievements, get_achievement_info, AchievementUnlockedEvent};
 
 const CONFIG_STORE_KEY: &str = "config";
 
@@ -72,23 +72,17 @@ pub async fn select_wsl_directory() -> Result<String, String> {
 
 #[tauri::command]
 pub async fn get_config(app: AppHandle) -> Result<HikariConfig, String> {
-    let store = app
-        .store("hikari-config.json")
-        .map_err(|e| e.to_string())?;
+    let store = app.store("hikari-config.json").map_err(|e| e.to_string())?;
 
     match store.get(CONFIG_STORE_KEY) {
-        Some(value) => {
-            serde_json::from_value(value.clone()).map_err(|e| e.to_string())
-        }
+        Some(value) => serde_json::from_value(value.clone()).map_err(|e| e.to_string()),
         None => Ok(HikariConfig::default()),
     }
 }
 
 #[tauri::command]
 pub async fn save_config(app: AppHandle, config: HikariConfig) -> Result<(), String> {
-    let store = app
-        .store("hikari-config.json")
-        .map_err(|e| e.to_string())?;
+    let store = app.store("hikari-config.json").map_err(|e| e.to_string())?;
 
     let value = serde_json::to_value(&config).map_err(|e| e.to_string())?;
     store.set(CONFIG_STORE_KEY, value);
@@ -107,7 +101,10 @@ pub async fn get_usage_stats(
 }
 
 #[tauri::command]
-pub async fn validate_directory(path: String, current_dir: Option<String>) -> Result<String, String> {
+pub async fn validate_directory(
+    path: String,
+    current_dir: Option<String>,
+) -> Result<String, String> {
     use std::path::Path;
 
     let path = Path::new(&path);
@@ -137,11 +134,17 @@ pub async fn validate_directory(path: String, current_dir: Option<String>) -> Re
 
     // Check if the path exists and is a directory
     if !expanded_path.exists() {
-        return Err(format!("Directory does not exist: {}", expanded_path.display()));
+        return Err(format!(
+            "Directory does not exist: {}",
+            expanded_path.display()
+        ));
     }
 
     if !expanded_path.is_dir() {
-        return Err(format!("Path is not a directory: {}", expanded_path.display()));
+        return Err(format!(
+            "Path is not a directory: {}",
+            expanded_path.display()
+        ));
     }
 
     // Return the canonicalized (absolute) path
@@ -152,7 +155,9 @@ pub async fn validate_directory(path: String, current_dir: Option<String>) -> Re
 }
 
 #[tauri::command]
-pub async fn load_saved_achievements(app: AppHandle) -> Result<Vec<AchievementUnlockedEvent>, String> {
+pub async fn load_saved_achievements(
+    app: AppHandle,
+) -> Result<Vec<AchievementUnlockedEvent>, String> {
     use chrono::Utc;
 
     // Load achievements from persistent store
@@ -163,9 +168,7 @@ pub async fn load_saved_achievements(app: AppHandle) -> Result<Vec<AchievementUn
     for achievement_id in &progress.unlocked {
         let mut info = get_achievement_info(achievement_id);
         info.unlocked_at = Some(Utc::now()); // We don't store timestamps, so just use now
-        events.push(AchievementUnlockedEvent {
-            achievement: info,
-        });
+        events.push(AchievementUnlockedEvent { achievement: info });
     }
 
     Ok(events)
@@ -184,12 +187,12 @@ pub async fn answer_question(
 
 #[tauri::command]
 pub async fn list_skills() -> Result<Vec<String>, String> {
-    use std::path::Path;
     use std::fs;
+    use std::path::Path;
 
     // Get the home directory
-    let home = std::env::var_os("HOME")
-        .ok_or_else(|| "Could not determine home directory".to_string())?;
+    let home =
+        std::env::var_os("HOME").ok_or_else(|| "Could not determine home directory".to_string())?;
 
     let skills_dir = Path::new(&home).join(".claude").join("skills");
 
@@ -200,8 +203,8 @@ pub async fn list_skills() -> Result<Vec<String>, String> {
 
     // Read the directory and collect skill names
     let mut skills = Vec::new();
-    let entries = fs::read_dir(&skills_dir)
-        .map_err(|e| format!("Failed to read skills directory: {}", e))?;
+    let entries =
+        fs::read_dir(&skills_dir).map_err(|e| format!("Failed to read skills directory: {}", e))?;
 
     for entry in entries {
         let entry = entry.map_err(|e| format!("Failed to read directory entry: {}", e))?;
@@ -244,7 +247,8 @@ struct GiteaRelease {
 #[tauri::command]
 pub async fn check_for_updates() -> Result<UpdateInfo, String> {
     const CURRENT_VERSION: &str = env!("CARGO_PKG_VERSION");
-    const RELEASES_API: &str = "https://git.nhcarrigan.com/api/v1/repos/nhcarrigan/hikari-desktop/releases";
+    const RELEASES_API: &str =
+        "https://git.nhcarrigan.com/api/v1/repos/nhcarrigan/hikari-desktop/releases";
 
     // Fetch releases from Gitea API
     let client = reqwest::Client::new();
@@ -264,8 +268,8 @@ pub async fn check_for_updates() -> Result<UpdateInfo, String> {
         .await
         .map_err(|e| format!("Failed to read response: {}", e))?;
 
-    let releases: Vec<GiteaRelease> = serde_json::from_str(&text)
-        .map_err(|e| format!("Failed to parse releases: {}", e))?;
+    let releases: Vec<GiteaRelease> =
+        serde_json::from_str(&text).map_err(|e| format!("Failed to parse releases: {}", e))?;
 
     // Find the latest non-prerelease, or fall back to latest prerelease
     let latest = releases