feat(evidence): structure v3 domain rules for review

docs/evidence.md

@@ -52,7 +52,13 @@ Canonical Curated Evidence v3 hides canonical machine metadata in an HTML commen
 whole review surface as real Markdown. GitHub therefore shows no frontmatter table. The body layout
 is deterministic for each Evidence kind: prose uses sections and paragraphs, scopes and enum values
 use wrapping lists, formulas use fenced SQL, supporting excerpts use blockquotes, and unresolved
-review items use dedicated blocks.
+review items use dedicated blocks. Long domain rules are split into readable paragraphs, labelled
+subsections, and lists at existing semicolon boundaries. Their exact original text remains canonical
+in an invisible marker, so the formatting cannot change their meaning or bytes.
+
+Preprocessing parses the unit first and builds semantic chunks from the typed payload. The vector
+store therefore receives the original rule text and not headings, list markers, or invisible
+presentation metadata.
 
 ```markdown
 <!-- tht:metadata:<canonical metadata> -->