Extract Vue frontend into separate container and add stp_wasm crate

Move Vue app from nginx/vue/ to top-level vue/ with its own Dockerfile,
update docker-compose configs and nginx proxy to serve from the new
container, and add initial Rust WASM crate (stp_wasm). Also fix .gitignore
to exclude Rust target/ directories.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

vue/src/views/home/Stamps.vue

@@ -0,0 +1,50 @@
+<script setup>
+import { ref } from "vue";
+
+import Touchscreen from "@/components/util/Touchscreen.vue";
+import Link from "@/components/text/Link.vue";
+import { shuffleArray } from "@/js/utils.js";
+
+let srcs = [
+    "/img/stamps/portal.gif",
+    "/img/stamps/miku.gif",
+    "/img/stamps/utau.gif",
+    "/img/stamps/teto.webp",
+    "/img/stamps/3ds.jpg",
+    "/img/stamps/fry.png",
+    "/img/stamps/ai.png",
+    "/img/stamps/rei.png",
+    "/img/stamps/tetris.gif",
+    "/img/stamps/tf2.gif",
+    "/img/stamps/demo.gif",
+];
+shuffleArray(srcs);
+</script>
+
+<template>
+    <Touchscreen>
+        <div class="flex flex-wrap tst">
+            <Link bare href="https://www.adam-french.co.uk">
+                <img src="https://www.adam-french.co.uk/img/stamps/mine.gif" />
+            </Link>
+            <Link bare href="https://jacobbarron.xyz">
+                <img
+                    src="https://jacobbarron.xyz/Banneh.gif"
+                    alt="jacobbarron.xyz"
+                />
+            </Link>
+            <img v-for="src in srcs" :src="src" />
+        </div>
+    </Touchscreen>
+</template>
+
+<style scoped>
+img {
+    width: 89px;
+    height: 59px;
+}
+
+.tst {
+    min-width: calc(89px * 4);
+}
+</style>