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/mdast-util-to-markdown/lib/handle/thematic-break.js

@@ -0,0 +1,21 @@
+/**
+ * @import {State} from 'mdast-util-to-markdown'
+ * @import {Parents, ThematicBreak} from 'mdast'
+ */
+
+import {checkRuleRepetition} from '../util/check-rule-repetition.js'
+import {checkRule} from '../util/check-rule.js'
+
+/**
+ * @param {ThematicBreak} _
+ * @param {Parents | undefined} _1
+ * @param {State} state
+ * @returns {string}
+ */
+export function thematicBreak(_, _1, state) {
+  const value = (
+    checkRule(state) + (state.options.ruleSpaces ? ' ' : '')
+  ).repeat(checkRuleRepetition(state))
+
+  return state.options.ruleSpaces ? value.slice(0, -1) : value
+}