feat: rebrand Hemmelig to paste.es for cloudhost.es

- Set Spanish as default language with ephemeral/encrypted privacy focus
- Translate all user-facing strings and legal pages to Spanish
- Replace Norwegian flag with Spanish flag in footer
- Remove Hemmelig/terces.cloud links, add cloudhost.es sponsorship
- Rewrite PrivacyPage: zero data collection, ephemeral design emphasis
- Rewrite TermsPage: Spanish law, RGPD, paste.es/CloudHost.es references
- Update PWA manifest, HTML meta tags, package.json branding
- Rename webhook headers to X-Paste-Event / X-Paste-Signature
- Update API docs title and contact to paste.es / cloudhost.es

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

prisma/migrations/20250626183203_add_username/migration.sql

@@ -0,0 +1,25 @@
+/*
+  Warnings:
+
+  - Added the required column `username` to the `user` table without a default value. This is not possible if the table is not empty.
+
+*/
+-- RedefineTables
+PRAGMA defer_foreign_keys=ON;
+PRAGMA foreign_keys=OFF;
+CREATE TABLE "new_user" (
+    "id" TEXT NOT NULL PRIMARY KEY,
+    "name" TEXT NOT NULL,
+    "username" TEXT NOT NULL,
+    "email" TEXT NOT NULL,
+    "emailVerified" BOOLEAN NOT NULL,
+    "image" TEXT,
+    "createdAt" DATETIME NOT NULL,
+    "updatedAt" DATETIME NOT NULL
+);
+INSERT INTO "new_user" ("createdAt", "email", "emailVerified", "id", "image", "name", "updatedAt") SELECT "createdAt", "email", "emailVerified", "id", "image", "name", "updatedAt" FROM "user";
+DROP TABLE "user";
+ALTER TABLE "new_user" RENAME TO "user";
+CREATE UNIQUE INDEX "user_email_key" ON "user"("email");
+PRAGMA foreign_keys=ON;
+PRAGMA defer_foreign_keys=OFF;