Initial commit: thbd-portal, duplicated from elmi-portal

Rebranded for Thunderbird Portal (THBD): numbering prefix EL->TH, all
"ELMI"/"ЭЛМИ" UI strings genericized, ELMI's real contract templates and
company legal/bank details removed (not applicable to this company), fresh
VAPID keypair and encryption key, fresh single-migration schema history.
Same architecture as elmi-portal: Web Push notifications, unread-chat app
badge, cookie-session auth.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Gh2UXUQUVBWroWEnn1FLFG

public/manifest.webmanifest

@@ -0,0 +1,14 @@
+{
+  "name": "Thunderbird Portal",
+  "short_name": "THBD",
+  "description": "Единый портал THBD: запросы, заявки, слежение, финансы.",
+  "start_url": "/inquiries",
+  "scope": "/",
+  "display": "standalone",
+  "background_color": "#f8f7fb",
+  "theme_color": "#6d28d9",
+  "icons": [
+    { "src": "/icon-192.png", "sizes": "192x192", "type": "image/png", "purpose": "any" },
+    { "src": "/icon-512.png", "sizes": "512x512", "type": "image/png", "purpose": "any" }
+  ]
+}