ihasmail 2.0: rebuild as Stalwart-first JMAP webmail

Replace the FastAPI/HTMX prototype with a Node/Hono session proxy and a
React 19/Vite SPA. Mail (conversation view, search operators, labels,
sanitised HTML, privacy image proxy, invites, undo send, templates),
calendar (month/week/day/agenda, invites, free/busy, categories,
context menus), contacts (JSContact, groups, vCard), files, Sieve filter
builder (incl. filter-from-message with retroactive apply), vacation,
identities with default + Reply-To, PWA/mobile layout, push via SSE,
in-memory mock Stalwart for dev, Docker + CI.

server/package.json

@@ -0,0 +1,24 @@
+{
+  "name": "@ihasmail/server",
+  "version": "2.0.0",
+  "private": true,
+  "type": "module",
+  "main": "dist/index.js",
+  "scripts": {
+    "dev": "tsx watch --clear-screen=false src/index.ts",
+    "build": "tsc -p tsconfig.json",
+    "start": "node dist/index.js",
+    "typecheck": "tsc -p tsconfig.json --noEmit",
+    "test": "tsx --test src/*.test.ts",
+    "mock": "tsx src/mock/index.ts"
+  },
+  "dependencies": {
+    "@hono/node-server": "^1.13.8",
+    "hono": "^4.7.4"
+  },
+  "devDependencies": {
+    "@types/node": "^22.13.10",
+    "tsx": "^4.19.3",
+    "typescript": "^5.7.3"
+  }
+}