ids theme: reliably render "Authors (Year):" as bold first line in bibliography

The old CSS hack inserted a line break before the FIRST ELEMENT CHILD of
each .csl-entry, plus a ::first-line tint. Which part of an entry
citeproc wraps in spans anchors depends on the entry type, so the break
landed arbitrarily -- e.g. mid-title in the DeLiKo entry or before the
final URL. Replace it with an explicit wrap: the theme template walks
the leading text nodes of each entry to the first "):" and marks them
as .csl-authors-year (display: block; bold; mid blue-gray), which is
both the bold first line and the line break. Entries without a year
marker are left untouched; spacing between entries is restored with a
0.5em margin (pandoc's div.csl-entry pins it to 0em otherwise). The
demo bibliography gains the DeLiKo citation as a regression case.

Change-Id: I196368e631a8870d63fe2022fb5cda3a0ad30072
diff --git a/examples/ids.Rmd b/examples/ids.Rmd
index 013b7bc..34c1f5f 100644
--- a/examples/ids.Rmd
+++ b/examples/ids.Rmd
@@ -103,7 +103,9 @@
     addExamples = T
   )
 ```
-  
+See [@kupietz_rkorapclient_2020]
+See [@kupietz-deliko2026]
+
 ## Source Code
 ### Print Collocation Analysis as DataTable