fix(version): inject APP_VERSION via Docker build-arg instead of git describe

In Docker builds, .git directory is not available in the container,
so git describe --tags fails and fallback is '0.0.0'. Now:
- build.sh passes --build-arg APP_VERSION=${tag} to frontend build
- Dockerfile accepts ARG APP_VERSION and sets ENV
- vite.config.js checks process.env.APP_VERSION first, then git describe

frontend/vite.config.js

@@ -3,6 +3,11 @@ import { defineConfig } from 'vite';
 import { execSync } from 'child_process';
 
 const APP_VERSION = (() => {
+	// 1. Use APP_VERSION env var (passed via Docker --build-arg or .env)
+	if (process.env.APP_VERSION && process.env.APP_VERSION !== '0.0.0') {
+		return process.env.APP_VERSION;
+	}
+	// 2. Fall back to latest git tag (works in local dev with .git)
 	try {
 		return execSync('git describe --tags --abbrev=0', { encoding: 'utf8' }).trim();
 	} catch {