A few tweaks to our report-only CSP header

Our CSP is in report-only mode, but we'd like to get it closer to being
enforcable. As a step in that direction I've opened a few pages in
production, audited the most common CSP warnings in the browser console,
and this should resolve them. These are all expected tools, our policy
has just bitrotted, or the vendor has changed their resources.

1. object_src: we can't include `none` alongside an actual value
2. connect_src: we load GA v4 from www.googletagmanager.com, but it wants
   to submit data to https://www.google-analytics.com
3. connect_src: helpscout beacon wants tosend data to a cloudfront
   distribution

CSP docs for Helpscout beacon (mentions the cloudfront domain):
https://docs.helpscout.com/article/815-csp-settings-for-beacon

CSP docs for datadog real user monitoring:
https://docs.datadoghq.com/integrations/content_security_policy_logs/

I also added some comments as context for future travelers.

config/initializers/content_security_policy.rb

@@ -19,7 +19,7 @@
 Rails.application.config.content_security_policy do |policy|
   policy.default_src :self
   policy.font_src    :self, "https://www2.buildkiteassets.com/"
-  policy.object_src  :none, "https://beacon-v2.helpscout.net"
+  policy.object_src  "https://beacon-v2.helpscout.net"
   policy.style_src   :self, :unsafe_inline, "https://beacon-v2.helpscout.net"
 
   policy.img_src(
@@ -44,6 +44,8 @@
   policy.script_src *policy.script_src, :unsafe_eval, "http://#{ ViteRuby.config.host_with_port }" if Rails.env.development?
 
   policy.connect_src(
+    "https://www.google-analytics.com",
+
     # allow AJAX queries against our search vendor
     "https://#{ENV['ALGOLIA_APP_ID']}-dsn.algolia.net",
     "https://#{ENV['ALGOLIA_APP_ID']}-1.algolianet.com",
@@ -52,14 +54,22 @@
 
     "https://cdn.segment.com/",
     "https://api.segment.io/",
+
+    # We have Datadog Real User Monitoring enabled
+    "https://rum.browser-intake-datadoghq.com",
+
+    # For collecting feedback from customers
     "https://emojicom.io/",
+
+    # helpscout beacon sends data to two places
     "https://beacon-v2.helpscout.net",
-    "https://rum.browser-intake-datadoghq.com"
+    "https://d3hb14vkzrxvla.cloudfront.net",
   )
 
   # Allow @vite/client to hot reload changes in development
   policy.connect_src *policy.connect_src, "ws://#{ ViteRuby.config.host_with_port }" if Rails.env.development?
 
+  # For collecting feedback from customers
   policy.frame_src(
     "https://cdn.emojicom.io/"
   )