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, 8 insertions, 1 deletions

diff --git a/internal/web/templates/admin/index.html b/internal/web/templates/admin/index.html
index 0e49e62..055671e 100644
--- a/internal/web/templates/admin/index.html
+++ b/internal/web/templates/admin/index.html
@@ -6,11 +6,18 @@
 </div>
 <div class="card">
 <table>
-  <tr><th>{{t "User"}}</th><th>{{t "Role"}}</th><th>{{t "Blog"}}</th><th>{{t "Since"}}</th><th>{{t "Actions"}}</th></tr>
+  <tr><th>{{t "User"}}</th><th>{{t "Role"}}</th><th>{{t "Blog"}}</th><th>{{t "Upload limit"}}</th><th>{{t "Since"}}</th><th>{{t "Actions"}}</th></tr>
   {{range .Data.users}}<tr{{if .Disabled}} class="disabled"{{end}}>
     <td>{{.Username}}{{if .Disabled}} <span class="tag">{{t "disabled"}}</span>{{end}}</td>
     <td>{{t .Role}}</td>
     <td>{{if .Subdomain}}<a href="/b/{{deref .Subdomain}}/">{{if eq (deref .Subdomain) "www"}}{{$.Data.cfg.BaseDomain}}{{else}}{{deref .Subdomain}}{{end}}</a> <a href="{{$.Data.cfg.BlogURL (deref .Subdomain)}}" target="_blank" class="muted">{{t "view"}} &#8599;</a>{{else}}<span class="muted">—</span>{{end}}</td>
+    <td class="nowrap">{{if .BlogID}}{{if .MaxUploadBytes}}{{size .MaxUploadBytes}}{{else}}{{size $.Data.defaultLimit}} <span class="muted">({{t "default"}})</span>{{end}}
+      <details class="inline"><summary class="mini">{{t "change"}}</summary>
+        <form method="post" action="/admin/blogs/{{deref64 .BlogID}}/upload-limit" class="inline">
+          <input type="hidden" name="_csrf" value="{{$.CSRF}}">
+          <input type="number" name="mb" min="1" max="1024" placeholder="MB" size="5"{{if .MaxUploadBytes}} value="{{mb .MaxUploadBytes}}"{{end}}>
+          <button class="mini">{{t "Set"}}</button> <span class="muted small">{{t "blank = default"}}</span>
+        </form></details>{{else}}<span class="muted">—</span>{{end}}</td>
     <td class="nowrap">{{date .CreatedAt}}</td>
     <td class="nowrap">
       {{if ne .ID $.User.ID}}