feat: Add automatic favicon fetching for companies (#13013)

## Summary

This Enterprise-only feature automatically fetches a favicon for
companies created with a domain, and adds a batch task to backfill
missing avatars for existing companies. The flow only targets companies
that do not already have an attached avatar, so existing avatars are
left untouched.


## Demo 



https://github.com/user-attachments/assets/d050334e-769f-4e46-b6e7-f7423727a192



## What changed

- Added `Avatar::AvatarFromFaviconJob` to build a Google favicon URL
from the company domain and fetch it through `Avatar::AvatarFromUrlJob`
- Triggered favicon fetching from `Company` with `after_create_commit`
- Added `Companies::FetchAvatarsJob` to batch existing companies that
are missing avatars
- Added `companies:fetch_missing_avatars` under `enterprise/lib/tasks`
- Kept the company-specific implementation inside the Enterprise
boundary
- Stubbed the new favicon request in unrelated specs that now hit this
callback indirectly
- Updated a couple of CI-sensitive specs that were failing due to
callback side effects / reload-safe exception assertions

## How to verify

1. Create a company in Enterprise with a valid domain and no avatar.
2. Confirm that a favicon-based avatar gets attached shortly after
creation.
3. Create another company with a domain and an avatar already attached.
4. Confirm that the existing avatar is not replaced.
5. Run `companies:fetch_missing_avatars`.
6. Confirm that existing companies without avatars get one, while
companies that already have avatars remain unchanged.

## Notes

- This change does not refresh or overwrite existing company avatars
- Favicon fetching only runs for companies with a present domain
- The branch includes the latest `develop`

---------

Co-authored-by: Muhsin Keloth <muhsinkeramam@gmail.com>
Co-authored-by: Sojan Jose <sojan@pepalo.com>

app/jobs/avatar/avatar_from_favicon_job.rb

@@ -0,0 +1,11 @@
+class Avatar::AvatarFromFaviconJob < ApplicationJob
+  queue_as :purgable
+
+  def perform(company)
+    return if company.domain.blank?
+    return if company.avatar.attached?
+
+    favicon_url = "https://www.google.com/s2/favicons?domain=#{company.domain}&sz=256"
+    Avatar::AvatarFromUrlJob.perform_now(company, favicon_url)
+  end
+end

app/jobs/companies/fetch_avatars_job.rb

@@ -0,0 +1,17 @@
+class Companies::FetchAvatarsJob < ApplicationJob
+  queue_as :low
+
+  def perform(account_id)
+    account = Account.find(account_id)
+    companies = account.companies.where.not(domain: [nil, ''])
+                       .left_joins(:avatar_attachment)
+                       .where(active_storage_attachments: { id: nil })
+
+    total_companies = companies.count
+    companies.find_each do |company|
+      Avatar::AvatarFromFaviconJob.perform_later(company)
+    end
+
+    Rails.logger.info "Queued #{total_companies} companies from account #{account_id} for favicon fetch"
+  end
+end