abstraction 2.1: a poem states its object range

- A poem is a container of verse, and stores its range of verse ocn,
  - its verse are the citable units with ocn.

- A note in the last verse of a poem previously was not gathered into
  the endnotes section, this now is fixed

Format 2.0 -> 2.1: the property is an addition, the poem is not a
citable object (but contans a range of objects), its verse are
(individual citable objects), and every reader checks the major version.
A 2.0 database reads as having no ranges.

(assisted by Claude-Code)

1 files changed, 35 insertions, 26 deletions

diff --git a/test/reference/abstraction/sisu-manual~sisu_markup.en.ssp b/test/reference/abstraction/sisu-manual~sisu_markup.en.ssp
index 4ea560e..6adc7b6 100644
--- a/test/reference/abstraction/sisu-manual~sisu_markup.en.ssp
+++ b/test/reference/abstraction/sisu-manual~sisu_markup.en.ssp
@@ -1,4 +1,4 @@
-% SiSU Document Abstraction v2.0
+% SiSU Document Abstraction v2.1
 % Source: sisu_markup.sst
 
 @source {
@@ -5031,6 +5031,18 @@
 .segment_epub_is: seg_4
 | ⑆!┨curly brace delimiter, resulting poem text output (broken into verse):┣!
 
+[0] poem
+.part: body
+.parent: 286
+.ocn_range: 291 291
+.ancestors: 1 54 0 0 110 261 286 0
+.ancestors_collapsed: 1 54 110 261 286 0 0 0
+.parent_lev: 6
+.is_of_type: block
+.sha256: E3B0C44298FC1C149AFBF4C8996FB92427AE41E4649B934CA495991B7852B855
+.segment_html_is: seg_4
+.segment_epub_is: seg_4
+
 [291] verse
 .part: body
 .parent: 286
@@ -5088,15 +5100,6 @@
 |                        death."'
 | 
 
-[291] poem
-.part: body
-.parent: 286
-.ancestors: 1 54 0 0 110 261 286 0
-.ancestors_collapsed: 1 54 110 261 286 0 0 0
-.parent_lev: 6
-.is_of_type: block
-.sha256: E3B0C44298FC1C149AFBF4C8996FB92427AE41E4649B934CA495991B7852B855
-
 [0] comment
 .part: comment
 .section: comment
@@ -5120,6 +5123,18 @@
 .segment_epub_is: seg_4
 | ⑆!┨curly brace delimiter, resulting poem text output (broken into verse):┣!
 
+[0] poem
+.part: body
+.parent: 286
+.ocn_range: 293 297
+.ancestors: 1 54 0 0 110 261 286 0
+.ancestors_collapsed: 1 54 110 261 286 0 0 0
+.parent_lev: 6
+.is_of_type: block
+.sha256: E3B0C44298FC1C149AFBF4C8996FB92427AE41E4649B934CA495991B7852B855
+.segment_html_is: seg_4
+.segment_epub_is: seg_4
+
 [293] verse
 .part: body
 .parent: 286
@@ -5191,26 +5206,29 @@
 | Purge them, scourge them, burnish brightly,
 |    Then in love set each one free.
 
-[297] poem
+[298] para
 .part: body
 .parent: 286
 .ancestors: 1 54 0 0 110 261 286 0
 .ancestors_collapsed: 1 54 110 261 286 0 0 0
 .parent_lev: 6
-.is_of_type: block
-.sha256: E3B0C44298FC1C149AFBF4C8996FB92427AE41E4649B934CA495991B7852B855
+.is_of_type: para
+.sha256: A9B484F8D854295F3471217F5EA897CC276457D444785772AD01E7776EFD3497
+.segment_html_is: seg_4
+.segment_epub_is: seg_4
+| ⑆!┨tics delimiter, resulting group text output:┣!
 
-[298] para
+[0] poem
 .part: body
 .parent: 286
+.ocn_range: 299 303
 .ancestors: 1 54 0 0 110 261 286 0
 .ancestors_collapsed: 1 54 110 261 286 0 0 0
 .parent_lev: 6
-.is_of_type: para
-.sha256: A9B484F8D854295F3471217F5EA897CC276457D444785772AD01E7776EFD3497
+.is_of_type: block
+.sha256: E3B0C44298FC1C149AFBF4C8996FB92427AE41E4649B934CA495991B7852B855
 .segment_html_is: seg_4
 .segment_epub_is: seg_4
-| ⑆!┨tics delimiter, resulting group text output:┣!
 
 [299] verse
 .part: body
@@ -5284,15 +5302,6 @@
 |    Then in love set each one free.
 | 
 
-[303] poem
-.part: body
-.parent: 286
-.ancestors: 1 54 0 0 110 261 286 0
-.ancestors_collapsed: 1 54 110 261 286 0 0 0
-.parent_lev: 6
-.is_of_type: block
-.sha256: E3B0C44298FC1C149AFBF4C8996FB92427AE41E4649B934CA495991B7852B855
-
 [304] heading :3
 .part: body
 .parent: 261