fix(agents): exclude opaque URI prose from import scans

docs/development/agent-workflow.md

@@ -71,7 +71,9 @@ HTML video, audio, source and track `src` assets and video posters use the same
 existence checks as images. Entity decoding uses full HTML text/attribute rules,
 including references whose semicolon may be omitted.
 Inline guidance imports are rejected after punctuation as well as whitespace.
-At-signs inside external URLs are excluded per HTML text node, preserving adjacent imports.
+At-signs inside external URIs (including opaque schemes such as mailto) are excluded
+per HTML text node, preserving adjacent imports. A colon directly before an import
+does not make that import a URI.
 A closing bracket followed by punctuation and an at-sign terminates a bare URL exclusion.
 Extensionless inline candidates are also imports when they resolve to repository files,
 checking the full filename before prefixes at ASCII/Unicode prose separators.