Remove cans feature; harden pw_/tok_ cookie flags (pre-release fixes) (#307)

docker-compose.yml

@@ -32,8 +32,8 @@ services:
       # Default: 5242880 (5 MiB).
       # PALETTE_MAX_TEXT: "5242880"
 
-      # Max size in bytes of a single can item (file/text inside a can) or a
-      # paste file attachment.
+      # Max size in bytes for multipart request parsing (paste file
+      # attachments are capped at 25 MB).
       # Default: 26214400 (25 MiB).
       # PALETTE_MAX_ITEM: "26214400"