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/factory-audit/assets/vale/styles/Kyberforge/DescriptionOpener.yml

@@ -1,5 +1,5 @@
 extends: existence
-message: "Description opens with '%s' — use an imperative 'Use when...' opener instead"
+message: "Description opens with '%s' — lead with the action or trigger, not 'This'"
 level: error
 scope: text.frontmatter.description
 ignorecase: true