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/dashboard/page_form.html b/internal/web/templates/dashboard/page_form.html
index 08c4a43..18d1119 100644
--- a/internal/web/templates/dashboard/page_form.html
+++ b/internal/web/templates/dashboard/page_form.html
@@ -8,7 +8,7 @@
     <label>{{t "Address"}} <span class="muted">({{t "leave empty to make one from the title; e.g."}} <code>about</code> → {{.BlogURL}}/about)</span><br>
       <input name="slug" value="{{.Data.page.Slug}}" pattern="[a-z0-9]([a-z0-9-]*[a-z0-9])?" maxlength="80"></label>
     <label for="ed-intro">{{t "Intro text"}} <span class="muted">({{t "Markdown, shown above the posts; optional"}})</span></label>
-    {{template "editor" (dict "name" "intro" "value" .Data.page.IntroMD "rows" 8 "tall" false "upload" (print "/b/" .Blog.Subdomain "/images/upload") "csrf" .CSRF)}}
+    {{template "editor" (dict "name" "intro" "value" .Data.page.IntroMD "rows" 8 "tall" false "upload" (print "/b/" .Blog.Subdomain "/files/upload") "csrf" .CSRF)}}
     <label class="check"><input type="checkbox" name="show_in_nav"{{if .Data.page.ShowInNav}} checked{{end}}> {{t "Show in menu"}}</label>
     <p class="actionrow">
       <button type="submit">{{t "Save"}}</button>