Add favicon and make profile picture editable per page

- Favicon: emoji-based inline SVG (🍯), the old /images/favicon/favicon.ico
  reference never resolved to an actual file.
- Profile picture (the circular image at the top) is now a per-page
  "profile_image" field editable in /admin, instead of a hardcoded
  URL in the template.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

data/links.json

@@ -5,6 +5,7 @@
     "subtitle2": "Here are all my important links for you!",
     "footer_label": "Cinnamon Version",
     "footer_href": "honey.html",
+    "profile_image": "https://c.tenor.com/rfib5QqA0ncAAAAd/tenor.gif",
     "sections": [
       {
         "id": "s_important",
@@ -96,6 +97,7 @@
     "subtitle2": "Some Stuff",
     "footer_label": "Honey Version",
     "footer_href": "index.html",
+    "profile_image": "https://c.tenor.com/rfib5QqA0ncAAAAd/tenor.gif",
     "sections": [
       {
         "id": "s_pangolin",