Turn the image library into a file library, with a per-blog upload limit

Bloggers want to attach PDFs, archives, audio and other files to posts,
not only images. The Images tab becomes Files: any type is accepted,
listed by kind with search, paging, rename and multi-file upload, and the
editor's paste/drop/"Insert file" takes anything (images are shown,
everything else becomes a link). The default limit goes from 5 to 10 MB
and the superadmin can override it per blog from /admin/.

Files stay in Postgres so one pg_dump is still the whole blog. The bytea
column is STORAGE EXTERNAL and /media streams it in substring() slices,
so serving never holds a whole file in memory whatever limit a blog gets.

Serving any type on the root domain, which carries the session cookie,
needs a policy: uploads are typed by sniffing (the extension may only
refine a generic sniff to an allowlisted type) and only images, PDF,
plain text, audio and video render inline; HTML, SVG, XML, scripts,
archives and binaries always go out as application/octet-stream with
Content-Disposition: attachment.

The body cap moves out of requireAuth into guardPOST, which runs after
withBlog has resolved the blog and so knows its limit.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Sd8UPWrvyYCLj97JexNw3A

1 files changed, 1 insertions, 1 deletions

diff --git a/internal/web/templates/admin/delete_user.html b/internal/web/templates/admin/delete_user.html
index 886ff1a..79bf2fc 100644
--- a/internal/web/templates/admin/delete_user.html
+++ b/internal/web/templates/admin/delete_user.html
@@ -2,7 +2,7 @@
 {{define "content"}}
 <div class="card narrow">
   <h1>{{tf "Delete %s?" .Data.target.Username}}</h1>
-  <p>{{t "This permanently deletes the user"}} <strong>{{.Data.target.Username}}</strong>{{t ", their blog, and every page, post and image in it."}}</p>
+  <p>{{t "This permanently deletes the user"}} <strong>{{.Data.target.Username}}</strong>{{t ", their blog, and every page, post and file in it."}}</p>
   <form method="post" action="/admin/users/{{.Data.target.ID}}/delete">
     <input type="hidden" name="_csrf" value="{{.CSRF}}">
     <p class="actionrow"><button type="submit" class="danger">{{t "Yes, delete everything"}}</button>