ai(rules[AGENTS]) Cap title/body, space why/what

why: Standardize commit guidance so titles stay scannable and
bodies wrap predictably across repos.

what:
- Cap subject at 50 chars (excluding trailing (#NN) PR ref)
- Wrap body lines at 72 chars
- Require a blank line between the why: and what: blocks

Author: tony

AGENTS.md

@@ -358,11 +358,16 @@ Format commit messages as:
 Scope(type[detail]): concise description
 
 why: Explanation of necessity or impact.
+
 what:
 - Specific technical changes made
 - Focused on a single topic
 ```
 
+Keep the subject ≤50 chars (excluding any trailing `(#NN)` PR ref); wrap
+body lines at ≤72 chars. Separate the `why:` and `what:` blocks with a
+blank line.
+
 Common commit types:
 - **feat**: New features or enhancements
 - **fix**: Bug fixes
@@ -380,6 +385,7 @@ Example:
 url/git(feat[GitURL]): Add support for custom SSH port syntax
 
 why: Enable parsing of Git URLs with custom SSH ports
+
 what:
 - Add port capture to SCP_REGEX pattern
 - Update GitURL.to_url() to include port if specified
@@ -400,6 +406,7 @@ git commit -m "$(cat <<'EOF'
 feat(Component[method]) add feature description
 
 why: Explanation of the change.
+
 what:
 - First change
 - Second change