refactor(factory): align agent-author and agent-audit with skill-author pattern

- agent-author: convert template comments from YAML (#) to HTML (<!-- -->)
  - Easier to spot and distinguish from functional comments
  - Add explicit "Delete template comments before shipping" reminders
  - Update SKILL.md Steps 2-3 with removal instruction

- agent-audit: add comment-discipline check
  - Flag excessive frontmatter documentation comments as padding
  - Mirrors skill-audit's body-discipline principle
  - Update coverage line to include comment-discipline dimension

This ensures agents follow the same comment-cleanup discipline as skills,
preventing template documentation from shipping with agent definitions.

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

plugins/kyberforge/skills/agent-author/SKILL.md

@@ -85,7 +85,7 @@ The script is file-by-file no-op — it skips any file that already exists.
 
 ### Step 2 — Fill in the Claude Code agent file (`<name>.md`)
 
-Open the scaffolded Claude Code file. Replace every `FILL IN:` placeholder.
+Open the scaffolded Claude Code file. Replace every `FILL IN:` placeholder. **Remove all template documentation comments from the YAML frontmatter after filling in required fields** — these are marked with `<!--` and `-->` and must be deleted before shipping.
 
 **`name`** — lowercase letters and hyphens only. Must be unique within the scope.
 
@@ -141,6 +141,8 @@ There are **two distinct Copilot agent formats** with different paths and field
 
 **`source_keys`** — add the same top-level list as the CC file when research sources were used. Omit when no research was used.
 
+**Remove all template documentation comments from the YAML frontmatter after filling in required fields** — these are marked with `<!--` and `-->` and must be deleted before shipping.
+
 The system prompt body should match the Claude Code version — the agent's task definition is the same across providers.
 
 ### Step 4 — Populate or delete `agents/sources.md` (plugin scope only)