fix(kyberforge): align primitive-author and factory-audit rule tiers

Second clean-context audit found author Must/Should and audit FAIL/SUGGESTION
tiers drifting apart, and author Musts the audit never checked.

- factory-audit: FAIL on absolute or bare relative hook script paths, an
  applyTo present but empty, and unbalanced braces/brackets in applyTo;
  judgment steps for dependency stem collisions, helper .json in hook dirs,
  unresolvable instruction links, prompt model slugs and second-person
  bodies; an unmatched glob drops to SUGGESTION; deliberate tier deviations
  recorded in hook-flow.md; validate.sh --help lists the three new modes;
  DescriptionOpener message no longer prescribes "Use when".
- primitive-author: deprecated routing, extra prompt keys and the prompt
  description contract become Shoulds; hook Musts gain "contributes an
  entry", no bare relative paths, and executable-when-run-directly;
  prompt Must 1 covers hardlinks; Vale prose FAILs resolved at close.
- forge: say "hook, instruction or prompt" rather than "apm primitive".

Refs #94

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KkT7RSDwDbmrM9T34b6sTi

plugins/kyberforge/.apm/skills/forge/references/author-routes.md

@@ -3,7 +3,7 @@ source_keys:
   - claude-code-subagents-docs
 ---
 
-# Routing a skill, agent or apm primitive to its author skill
+# Routing a skill, agent, hook, instruction or prompt to its author skill
 
 Reached from `SKILL.md` Step 2 when the classified artifact is a skill, an agent/subagent
 definition, or a hook, instruction or prompt. Route a skill to `skill-author`, an agent to