feat(web): add Claude installations endpoint and debug command

- Add /api/settings/claude/installations endpoint to web server
- Implement list_claude_installations handler
- Add 'just debug' command for troubleshooting Claude binary detection

This fixes the HTTP 404 error when accessing Claude Installation settings
in web mode. The debug command helps users verify their Claude installation
is detected correctly.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: 2 people

src-tauri/src/web_server.rs

@@ -151,6 +151,17 @@ async fn check_claude_version() -> Json<ApiResponse<serde_json::Value>> {
     Json(ApiResponse::success(version_status))
 }
 
+/// List all available Claude installations on the system
+async fn list_claude_installations() -> Json<ApiResponse<Vec<crate::claude_binary::ClaudeInstallation>>> {
+    let installations = crate::claude_binary::discover_claude_installations();
+
+    if installations.is_empty() {
+        Json(ApiResponse::error("No Claude Code installations found on the system".to_string()))
+    } else {
+        Json(ApiResponse::success(installations))
+    }
+}
+
 /// Get system prompt - return default for web mode
 async fn get_system_prompt() -> Json<ApiResponse<String>> {
     let default_prompt = "You are Claude, an AI assistant created by Anthropic. You are running in web server mode.".to_string();
@@ -646,6 +657,7 @@ pub async fn create_web_server(port: u16) -> Result<(), Box<dyn std::error::Erro
         // Settings and configuration
         .route("/api/settings/claude", get(get_claude_settings))
         .route("/api/settings/claude/version", get(check_claude_version))
+        .route("/api/settings/claude/installations", get(list_claude_installations))
         .route("/api/settings/system-prompt", get(get_system_prompt))
 
         // Session management