Add /health endpoint for fast health checks, fix cold start timeout

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

exiftree/urls.py

@@ -121,6 +121,7 @@ urlpatterns = [
     path("admin/", admin.site.urls),
     path("sitemap.xml", sitemap, {'sitemaps': sitemaps}, name='sitemap'),
     path("robots.txt", TemplateView.as_view(template_name='robots.txt', content_type='text/plain')),
+    path("health", lambda r: HttpResponse("ok")),
     path("favicon.ico", lambda r: HttpResponse(status=204)),
     path("apple-touch-icon.png", lambda r: HttpResponse(status=204)),
     path("apple-touch-icon-precomposed.png", lambda r: HttpResponse(status=204)),

fly.toml

@@ -34,7 +34,7 @@ primary_region = 'iad'
     interval = 10000
     grace_period = "5s"
     method = "GET"
-    path = "/"
+    path = "/health"
     timeout = 2000
 
 [env]