Few small fixes for the Website service (#23)

This PR contains the work done to address small fixes.

To provide further details:

* HTML template
  * Removed the duplicate charset <meta> tag from the Page protocol's head property.

* Router
  * Enabled auto-generated HEAD endpoints so every GET route gets a HEAD sibling. Uptime monitors and crawlers probing with HEAD now receive the page's status and headers instead of a 404.

* Docker
  * Pinned the asset optimizer versionsvia build args so minified output is reproducible for a given Dockerfile commit.
  * Narrowed the build context copied into the release stage, only package manifests and Swift sources are copied. Static assets come from the separate assets stage after the binary is built.
  * svgo now minifies all SVGs recursively rather than just icon.svg, and the staging step creates Resources/Static explicitly instead of conditionally moving the unminified sources.
  * Added curl to the runtime image (needed for the container healthcheck) and .claude to .dockerignore.

* Docker-compose
  * Added a `healthcheck` to the website service hitting GET /health (liveness only), so Compose reports process health without coupling container health to database reachability.

Reviewed-on: rock-n-code/loud-amsterdam#23
Co-authored-by: Javier Cicchelli <javier@rock-n-code.com>
Co-committed-by: Javier Cicchelli <javier@rock-n-code.com>

Services/Website/Tests/App/AppTests.swift

@@ -48,6 +48,22 @@ struct AppTests {
         }
     }
 
+    @Test
+    func `landing page to answer a head request`() async throws {
+        try await app(
+            staticFilesPath: staticFilesPath
+        ).test(.router) { client in
+            try await client.execute(
+                uri: "/",
+                method: .head
+            ) { response in
+                #expect(response.status == .ok)
+                #expect(response.headers[.contentType] == "text/html; charset=utf-8")
+                #expect(response.body.readableBytes == 0)
+            }
+        }
+    }
+
     @Test
     func `health check to be served at the health path`() async throws {
         try await app(