Add a rule under page and post titles, and tags shown with a # in front

Two Design tab options in the Posts section. The title rule reuses the
header rule's kinds (line, dots, stripes): a body class blog.css draws
from — width and style only, so the theme CSS's link colour is not reset —
ending at a floated thumbnail instead of running under it. The tag hash is
applied everywhere tags are listed: under posts, in both tag modules and in
the tag page's title.

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

1 files changed, 9 insertions, 1 deletions

diff --git a/AGENTS.md b/AGENTS.md
index d4a9284..bfed5cb 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -184,7 +184,15 @@ internal/web/         server.go (host router, middleware, render helpers)
   as tall as the brand and old browsers agree) in `currentColor`, i.e. the
   header text colour; hidden on phones so a long title can wrap. `NavStyle`
   `plain` is regular weight + underline for the menu links (blog.css makes
-  them bold).
+  them bold). `TitleRule` (`none` | `line` | `dots` | `stripes`) is the same
+  rule under page and post titles (`.page-title`, `.post-title`): a body
+  class from `Theme.TitleRuleClass` (`titles-<kind>`) that blog.css draws
+  (border width/style only — never the shorthand, or it would reset the
+  colour; stripes are an `::after` gradient in `currentColor`), coloured
+  by the theme CSS in the link colour; `overflow:hidden` ends it at a floated
+  thumbnail. `TagHash` lists tags as `#name` wherever they appear: the
+  `posttags` partial (takes `dict "tags" … "hash" …`), the two tag modules
+  and the tag page title (`tagname` template func).
   **Custom fonts** (`CustomFont`, `CustomHeadingFont`: font file ids or ""):
   a chosen file is declared as `@font-face` (`"BlogFont"` / `"BlogHeadingFont"`,
   `src:url(/media/<id>)`, same-origin so no CORS) and put first in the stack,