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/Notes.vue

@@ -0,0 +1,75 @@
+<script setup>
+import Markdown from "@/components/util/Markdown.vue";
+import { ref, onMounted } from "vue";
+import axios from "axios";
+import { useRoute } from "vue-router";
+
+const file = ref(null);
+const filename = ref("");
+const last_edited = ref(null);
+
+// if the address is https://www.adam-french.co.uk/notes/PATH
+// request from https://www.adam-french.co.uk/api/notes/PATH
+const route = useRoute();
+const pathArray = route.params.path;
+const path = Array.isArray(pathArray) ? pathArray.join("/") : pathArray;
+const url = `/api/notes/${path}`;
+
+function getFilename(headers) {
+    const disposition = headers["content-disposition"];
+    if (!disposition) return null;
+
+    const match = disposition.match(/filename="?([^"]+)"?/);
+    return match ? match[1] : null;
+}
+
+async function fetchFile() {
+    const response = await axios.get(url, { responseType: "blob" });
+    filename.value = getFilename(response.headers);
+
+    const lastModified = response.headers["last-modified"];
+    last_edited.value = lastModified ? new Date(lastModified) : null;
+
+    if (filename.value.toLowerCase().endsWith(".md")) {
+        const text = await response.data.text();
+        file.value = fixLinks(text);
+    } else {
+        file.value = response.data;
+    }
+}
+
+function fixLinks(filedata) {
+    return filedata.replace(/\[([^\]]+)\]\(([^)]+)\)/g, (match, text, url) => {
+        if (
+            url.startsWith("http://") ||
+            url.startsWith("https://") ||
+            url.startsWith("#") ||
+            url.startsWith("./") ||
+            url.startsWith("../") ||
+            url.startsWith("//")
+        ) {
+            return match;
+        }
+
+        return `[${text}](/notes/${url})`;
+    });
+}
+
+onMounted(fetchFile);
+</script>
+
+<template>
+    <main class="items-center flex flex-col">
+        <div class="background halftone" />
+        <div
+            v-if="file"
+            class="a4page-portrait border-primary-1 flex flex-col relative overflow-scroll gap-1 bg-bg_primary"
+        >
+            <h1>{{ filename }}</h1>
+            <small>{{ last_edited }}</small>
+            <Markdown class="flex-1 border-box text-wrap" :source="file" />
+        </div>
+
+        <div v-else>Loading…</div>
+    </main>
+</template>