media assets: remove image links for deleted images.

Don't show dead direct image links, reverse search links, or source links for deleted media assets.

app/models/media_asset.rb

@@ -27,6 +27,8 @@ class MediaAsset < ApplicationRecord
   scope :public_only, -> { where(is_public: true) }
   scope :private_only, -> { where(is_public: false) }
   scope :without_ai_tags, -> { where.not(AITag.where("ai_tags.media_asset_id = media_assets.id").select(1).arel.exists) }
+  scope :removed, -> { where(status: [:deleted, :expunged]) }
+  scope :expired, -> { processing.where(created_at: ..4.hours.ago) }
 
   # Processing: The asset's files are currently being resized and distributed to the backend servers.
   # Active: The asset has been successfully uploaded and is ready to use.
@@ -51,8 +53,6 @@ class MediaAsset < ApplicationRecord
 
   before_create :initialize_file_key
 
-  scope :expired, -> { processing.where(created_at: ..4.hours.ago) }
-
   def self.prune!
     expired.update_all(status: :failed)
   end
@@ -321,6 +321,10 @@ class MediaAsset < ApplicationRecord
       end
     end
 
+    def removed?
+      deleted? || expunged?
+    end
+
     # @return [Mime::Type] The file's MIME type.
     def mime_type
       Mime::Type.lookup_by_extension(file_ext)