Add a favicon and rework the Design page

Blogs had no icon at all, and browsers probing /favicon.ico ended up
rendering the 404 page. Ship a default paper & ink icon (svg + png) and
let each blog replace it from the Design page; /favicon.ico now serves
the default or redirects to the blog's own image. ICO uploads accepted.

The Design page gains colour schemes, reset to defaults, thumbnail
image pickers, jump links and a sticky save bar, plus new options:
heading font, link underline/hover, content box style and padding,
header image height, post dates and format, footer RSS toggle, menu
alignment/style/hover and sidebar width. The Menu card picks the
position with illustrated tiles and shows only the options that apply
to it, using CSS :checked rules rather than JavaScript.

All new defaults reproduce the previous look, so existing blogs are
unchanged until edited. Theme is jsonb, so no migration.

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/blog/post.html b/internal/web/templates/blog/post.html
index 83ce782..5fa8ca4 100644
--- a/internal/web/templates/blog/post.html
+++ b/internal/web/templates/blog/post.html
@@ -2,7 +2,7 @@
 {{define "content"}}
 <article class="post single">
   <h1 class="post-title">{{.Data.post.Title}}</h1>
-  <p class="post-date">{{date .Data.post.CreatedAt}} &middot; <a href="{{if .Data.page.IsHome}}/{{else}}/{{.Data.page.Slug}}{{end}}">{{.Data.page.Title}}</a></p>
+  <p class="post-date">{{if .Data.theme.ShowDates}}{{.Data.theme.FormatDate .Data.post.CreatedAt}} &middot; {{end}}<a href="{{if .Data.page.IsHome}}/{{else}}/{{.Data.page.Slug}}{{end}}">{{.Data.page.Title}}</a></p>
   <div class="post-body">{{html .Data.post.BodyHTML}}</div>
 </article>
 {{end}}