Follow beamer's model for notes, and lay the page out like it

Notes were rendered as a bullet list, which beamer does not do. Reading
beamerbasenotes.sty: a plain \note appends its text to a running block with
no separator at all, and \note[item] accumulates separately into an
enumerate printed after that block.

Match both. talk-notes.sty takes \note<spec>[item]{text}, as beamer does,
and records which kind it is. The one deviation is a paragraph break
between plain notes instead of running them together, which is easier to
read on a page.

The notes half is laid out like beamer's too: a grey band across the head
carrying the section and the position in the talk, the current slide flush
into the outer corner, and the notes below. The heading is set in the
sans face against the roman body so it reads as apparatus rather than as
part of the notes.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

slides_template/talk-notes.sty

@@ -58,21 +58,25 @@
       { SUBSECTION ~ \tl_to_str:N \g__talknotes_subsection_tl }
   }
 
-% \note[<overlay spec>]{text}
+% \note<overlay spec>[item]{text}
+%
+% Follows beamer's interface. A plain \note contributes running text; \note[item]
+% contributes an entry to a numbered list printed after that text.
 %
 % The body is written out stringified, so LaTeX markup inside a note survives
 % to be typeset again on the notes page. A note is recorded once per slide of
 % its frame (the frame body is re-run for each), so mknotes deduplicates.
 % Records are bracketed by ENDNOTE because a long note may be broken across
 % output lines.
-\NewDocumentCommand \note { d<> +m }
+\NewDocumentCommand \note { d<> o +m }
   {
     \iow_now:Nx \g__talknotes_iow
       {
         NOTE ~ FRAME ~ \int_use:N \g__talk_frame_int |
-        SPEC ~ \IfNoValueTF {#1} { - } { \tl_to_str:n {#1} }
+        SPEC ~ \IfNoValueTF {#1} { - } { \tl_to_str:n {#1} } |
+        KIND ~ \IfNoValueTF {#2} { text } { \tl_to_str:n {#2} }
       }
-    \iow_now:Nx \g__talknotes_iow { TEXT ~ \tl_to_str:n {#2} }
+    \iow_now:Nx \g__talknotes_iow { TEXT ~ \tl_to_str:n {#3} }
     \iow_now:Nn \g__talknotes_iow { ENDNOTE }
   }