fix(kyberforge): align the audit word ceiling and drop the fragile --config

Three divergences between what the audit skills claim and what the hooks
enforce, each of which fails silently rather than loudly:

- `skill-size-check.sh` blocked at 2900 words while `validate.sh` checked only
  the 500-line ceiling, so `/skill-audit` could report a skill ready to ship
  that the commit hook then rejected. `validate.sh` now checks the same pair on
  the same inclusive terms; the constants are duplicated with a comment naming
  the other file, because a plugin skill's scripts cannot read outside the
  plugin directory once installed to the cache.
- Both audit skills' Step 1 passed `--config assets/vale/.vale.ini`, which is
  redundant (the wrapper self-locates its sibling config) and fragile: an agent
  that resolves the script path against the skill directory but not the config
  path gets E100, exit 2, which the surrounding fallback clause misreads as
  "vale unavailable" and downgrades to full LLM judgment with no signal.
- The external-consumer test registered only the two Vale hooks, never the
  third shipped hook, so a lost executable bit would have broken every consumer
  while the local suite stayed green. Verified by mutation: `chmod 644` on the
  copied script now turns three passes into two failures.

Also corrects the size hook's calibration comment, which claimed ~5.7-6.5
characters per word against a corpus whose measured median is 6.79 — the stated
upper bound sat below the median, so the "calibrated with margin" claim was
inverted for prose-dense files. MAX_WORDS is unchanged pending a decision; the
comment is now explicit that the gate holds under 5,000 tokens for typical
prose density, not for any file.

Refs: #85

plugins/kyberforge/skills/skill-audit/scripts/validate.sh

@@ -133,12 +133,28 @@ else:
     if desc:
         ok("description has no unfilled placeholders")
 
-# SKILL.md line count
+# SKILL.md size ceilings (agentskills.io skill-authoring.md: 500 lines,
+# ~5,000 tokens). Both constants are DUPLICATED from the repo-root pre-commit
+# hook scripts/skill-size-check.sh — a plugin skill's scripts cannot read files
+# outside the plugin directory once the plugin is cache-installed, so there is
+# no single source to share. Keep the two in sync by hand: if they drift, this
+# audit will report a skill ready to ship that the commit hook then rejects.
+MAX_LINES = 500
+MAX_WORDS = 2900  # word-count proxy for the ~5,000-token ceiling
+
 line_count = len(content.splitlines())
-if line_count <= 500:
-    ok(f"SKILL.md line count {line_count} (limit: 500)")
+if line_count <= MAX_LINES:
+    ok(f"SKILL.md line count {line_count} (limit: {MAX_LINES})")
 else:
-    fail(f"SKILL.md line count {line_count} — exceeds 500-line limit")
+    fail(f"SKILL.md line count {line_count} — exceeds {MAX_LINES}-line limit")
+
+# str.split() with no argument splits on runs of whitespace, matching the
+# `wc -w` the hook uses, and counts the whole file including frontmatter.
+word_count = len(content.split())
+if word_count <= MAX_WORDS:
+    ok(f"SKILL.md word count {word_count} (limit: {MAX_WORDS}, proxy for ~5,000 tokens)")
+else:
+    fail(f"SKILL.md word count {word_count} — exceeds {MAX_WORDS}-word limit (proxy for ~5,000 tokens)")
 
 # Body unfilled placeholders
 body = content[body_start:]