Frontend uudelleenrakennettu: Astro-komponentit, Wasm pääsäikeessä, ei Workeria

Vanha frontend siirretty temp/. Uusi rakenne:
- StatusBar.astro, Terminal.astro, Editor.astro, Guide.astro
- global.css erillinen
- Wasm pääsäikeessä (ei Worker — yksinkertainen, debugattava)
- Tab-completion, dropdown, projektikortti, Monaco, GUIDE.md
- Ei tokenisointia eikä koodilaboratoriota

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

network-poc/frontend/node_modules/decode-named-character-reference/index.dom.js

@@ -0,0 +1,32 @@
+/// <reference lib="dom" />
+
+/* global document */
+
+const element = document.createElement('i')
+
+/**
+ * @param {string} value
+ * @returns {string | false}
+ */
+export function decodeNamedCharacterReference(value) {
+  const characterReference = '&' + value + ';'
+  element.innerHTML = characterReference
+  const character = element.textContent
+
+  // Some named character references do not require the closing semicolon
+  // (`&not`, for instance), which leads to situations where parsing the assumed
+  // named reference of `&notit;` will result in the string `¬it;`.
+  // When we encounter a trailing semicolon after parsing, and the character
+  // reference to decode was not a semicolon (`&semi;`), we can assume that the
+  // matching was not complete.
+  if (
+    character.charCodeAt(character.length - 1) === 59 /* `;` */ &&
+    value !== 'semi'
+  ) {
+    return false
+  }
+
+  // If the decoded string is equal to the input, the character reference was
+  // not valid.
+  return character === characterReference ? false : character
+}