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/components/Navbar.vue

@@ -0,0 +1,67 @@
+<script setup>
+import Headline from "@/components/text/Headline.vue";
+import { computed } from "vue";
+import { useRoute } from "vue-router";
+
+const route = useRoute();
+
+const parentPath = computed(() => {
+    const segments = route.path.split("/").filter(Boolean);
+    if (segments.length == 1) {
+        return "/";
+    } else {
+        segments.pop();
+        return segments.length ? "/" + segments.join("/") : null;
+    }
+});
+
+const inHome = computed(() => {
+    return route.path == "/" || route.path == "/stp";
+});
+
+const faces = [
+    "^_^",
+    "¯\\_(ツ)_/¯",
+    "(◕‿◕✿)",
+    "ಠ_ಠ",
+    "ʘ‿ʘ",
+    "^̮^",
+    ">_>",
+    "¬_¬",
+    "˙ ͜ʟ˙",
+    "( ͡° ͜ʖ ͡°)",
+    "[̲̅$̲̅(̲̅5̲̅)̲̅$̲̅]",
+    "(ง'̀-'́)ง",
+    "\ (•◡•) /",
+    "( ͡ᵔ ͜ʖ ͡ᵔ )",
+    "ᕙ(⇀‸↼‶)ᕗ",
+    "⚆ _ ⚆",
+    "(｡◕‿◕｡)",
+    "(╯°□°)╯︵ ʞooqǝɔɐɟ",
+    "̿ ̿ ̿'̿'\̵͇̿̿\з=(•_•)=ε/̵͇̿̿/'̿'̿ ̿",
+    "(☞ﾟヮﾟ)☞ ☜(ﾟヮﾟ☜)",
+];
+const faces_string = faces.join("      ");
+</script>
+
+<template>
+    <nav class="flex flex-row w-full h-fit border border-primary bg-bg_primary">
+        <RouterLink class="bdr-2 bg-bg_primary" to="/" v-if="!inHome">
+            <span>HOME</span>
+        </RouterLink>
+        <RouterLink class="bdr-2 bg-bg_primary" v-if="parentPath" :to="parentPath">
+            <span>UP</span>
+        </RouterLink>
+        <Headline class="border flex-1 max-w-full">
+            <code class="whitespace-pre">{{ faces_string }}</code>
+        </Headline>
+    </nav>
+</template>
+
+<style scoped>
+.left {
+    position: fixed;
+    top: 0;
+    left: 0;
+}
+</style>