refactor: Move Astro to root, use PORT env (default 80), allow all hosts

- Move Astro files from dealplustech-astro/ to project root
- Update Dockerfile: PORT environment variable (default 80)
- Add vite.config.ts with allowedHosts: true
- Matches nixpacks behavior for Easypanel deployment
- No hardcoded ports or domains

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
+}