fix(lint): make the Vale prefilter work for external consumers

pre-commit prefixes only entry[0] with the hook-repo clone path
(cmd = (prefix.path(cmd[0]), *cmd[1:])), so the --config argument in
.pre-commit-hooks.yaml resolved against the *consuming* repo's root
and hard-failed every external run with E100. Two of the three hooks
ADR-0014 promises were unusable.

vale-wrap.sh now self-locates its config from BASH_SOURCE when no
--config is supplied; an explicit --config still wins in all three
argv forms and stays cwd-relative. Both manifests drop the argument
and are kept byte-identical: the local repo: local config resolved
--config correctly only because the consuming repo *was* this repo,
and that divergence is why three review rounds missed the defect.

Also in the wrapper:
- replace GNU-only `realpath -m` with a portable abspath helper; -m is
  load-bearing (dest does not exist yet), so BSD realpath aborted the
  script under set -e on macOS
- walk directory arguments instead of passing them through unflattened,
  which reported a clean 0-error run for files that fail when named
  explicitly
- read/write with errors='surrogateescape' so one non-UTF-8 .md under a
  directory argument cannot abort the hook

New test-vale-hooks-consumer.sh builds the hook repo from the working
tree and points a file:// consumer at it, covering the manifest as a
hook repo for the first time.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MCQ648fLSFXPHGZdQ8gn58

.pre-commit-hooks.yaml

@@ -1,14 +1,14 @@
 -   id: kyberforge-vale-audit-skill
     name: Kyberforge Vale prose audit (SKILL.md)
     description: Deterministic prose-pattern prefilter for kyberforge's skill-audit, via its own bundled Vale config/styles
-    entry: plugins/kyberforge/skills/skill-audit/scripts/vale-wrap.sh --config plugins/kyberforge/skills/skill-audit/assets/vale/.vale.ini
+    entry: plugins/kyberforge/skills/skill-audit/scripts/vale-wrap.sh
     language: script
     files: '(^|/)SKILL\.md$'
 
 -   id: kyberforge-vale-audit-agent
     name: Kyberforge Vale prose audit (agent files)
     description: Deterministic prose-pattern prefilter for kyberforge's agent-audit, via its own bundled Vale config/styles
-    entry: plugins/kyberforge/skills/agent-audit/scripts/vale-wrap.sh --config plugins/kyberforge/skills/agent-audit/assets/vale/.vale.ini
+    entry: plugins/kyberforge/skills/agent-audit/scripts/vale-wrap.sh
     language: script
     files: '(^|/)agents/[^/]+\.md$|\.agent\.md$'