feat: add standalone marketplace PWA build

Adds a standalone Nostr marketplace PWA at market.${domain}, built
from the existing src/modules/market plugin. Same standalone pattern
as wallet/chat/castle/activities:
- market.html entry, vite.market.config.ts (outDir: dist-market,
  manifest id: market-app, theme: red #dc2626 — Muladhara chakra)
- src/market-app/{main.ts, app.ts, app.config.ts, App.vue} bootstraps
  base + market only, with acceptTokenFromUrl for shared auth from hub
- npm run dev:market / build:market / preview:market
- main app SW denylist extended with /market/, /cart/, /checkout/

Closes #18.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

package.json

@@ -15,6 +15,9 @@
     "dev:castle": "vite --host --config vite.castle.config.ts",
     "build:castle": "vue-tsc -b && vite build --config vite.castle.config.ts",
     "preview:castle": "vite preview --host --config vite.castle.config.ts",
+    "dev:market": "vite --host --config vite.market.config.ts",
+    "build:market": "vue-tsc -b && vite build --config vite.market.config.ts",
+    "preview:market": "vite preview --host --config vite.market.config.ts",
     "electron:dev": "concurrently \"vite --host\" \"electron-forge start\"",
     "electron:build": "vue-tsc -b && vite build && electron-builder",
     "electron:package": "electron-builder",