fix: merge jte extension refactor with static serving features

- Move JteStaticServing to dev.relism.flash package
- Fix imports in HttpStatus and test files
- Add fluent config methods to JteExtension (templateRoot, serveStatics, staticPrefix, etc.)
- Implement routes() for static asset serving with HEAD support
- Include Main.java entry point

flash/src/main/java/dev/relism/flash/Main.java

@@ -0,0 +1,48 @@
+package dev.relism.flash;
+
+import dev.relism.flash.extension.FlashApp;
+import dev.relism.flash.http.ContentType;
+import dev.relism.flash.http.HttpMethod;
+import dev.relism.flash.routing.Middleware;
+import lombok.extern.slf4j.Slf4j;
+
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+@Slf4j
+public class Main {
+
+    private static final int  PORT       = 8080;
+    private static final Path UPLOAD_DIR = Path.of(System.getProperty("java.io.tmpdir"), "flash-uploads");
+
+    private static final Middleware CORS = next -> (req, res) -> {
+        res
+                .header("Access-Control-Allow-Origin",  "*")
+                .header("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS")
+                .header("Access-Control-Allow-Headers", "Content-Type, Authorization");
+        if (req.method() == HttpMethod.OPTIONS) { res.status(204); return null; }
+        return next.handle(req, res);
+    };
+
+    private static final Middleware ACCESS_LOG = next -> (req, res) -> {
+        long start = System.nanoTime();
+        try {
+            return next.handle(req, res);
+        } finally {
+            log.info("{} {} -> {}ms", req.method(), req.path(),
+                    (System.nanoTime() - start) / 1_000_000.0);
+        }
+    };
+
+
+    public static void main(String[] args) throws Exception {
+        Files.createDirectories(UPLOAD_DIR);
+
+        FlashApp.create(PORT)
+                .get("/plaintext", (req, res) -> {
+                    res.type(ContentType.TEXT_PLAIN);
+                    return "Hello, World!";
+                }, ACCESS_LOG, CORS)
+                .startAndBlock();
+    }
+}

flash/src/main/java/dev/relism/flash/http/HttpStatus.java

@@ -1,10 +1,5 @@
 package dev.relism.flash.http;
 
-import dev.relism.models.Request;
-import dev.relism.models.Response;
-import dev.relism.routing.GET;
-import dev.relism.routing.Route;
-
 import java.nio.charset.StandardCharsets;
 import java.util.List;