Expand exemplar corpus to 14 across 8 CMOS 18 source types

Add 11 new exemplars pulled verbatim from the CMOS official quick guide
(chicagomanualofstyle.org/tools_citationguide/citation-guide-1.html):

- book_two_authors_binder: Binder & Kidder (two-author book)
- book_chapter_doyle: Doyle in Marks & Parkin (chapter in edited volume,
  no page range per CMOS 18)
- book_translated_liu: Liu Xinwu, trans. Tiang (translated book, non-
  Western name not comma-inverted)
- book_edition_borel: Borel, 2nd ed. via EBSCOhost (edition + database)
- book_ebook_roy: Roy, Kindle format
- journal_many_authors_snyder: 7 authors in PLOS ONE, exercises the
  CMOS 18 "first 3 + et al." threshold and article-ID page format
- magazine_mead: New Yorker (tests leading-"The" drop)
- newspaper_blum: NYT with URL (tests abbreviation expansion)
- social_media_cmos_facebook: Facebook post with case preservation
- podcast_ober: Pushkin podcast with season/episode/duration
- video_cowan_ted: TED Talk with venue and duration

Every exemplar is marked canary=true — we want byte-exact regression
detection on all of them. Source citations and CMOS rule justifications
are in the TOML doc comments.

All 14 canonical outputs lint clean under LINTER_VERSION v0.2.0. The
harness will score them in the following commit.

exemplars/book_edition_borel.toml

@@ -0,0 +1,16 @@
+# Source: CMOS official citation guide (chicagomanualofstyle.org), 18th ed.
+# Book in a specific edition, accessed via a database.
+source = "CMOS official citation guide (chicagomanualofstyle.org/tools_citationguide/citation-guide-1.html)"
+type = "book"
+tags = ["book", "edition", "database"]
+canary = true
+messy_input = "Borel, Brooke. The Chicago Guide to Fact-Checking, second edition. Chicago: University of Chicago Press, 2023. Accessed via EBSCOhost."
+expected_bibliography = "Borel, Brooke. *The Chicago Guide to Fact-Checking*. 2nd ed. University of Chicago Press, 2023. EBSCOhost."
+
+[canonical]
+author = "Borel, Brooke"
+title = "The Chicago Guide to Fact-Checking"
+edition = "2nd ed."
+publisher = "University of Chicago Press"
+year = 2023
+database = "EBSCOhost"