fix(lint): flatten multi-line frontmatter descriptions before Vale runs

Vale's text.frontmatter.description scope silently stops matching once
the description is a YAML block scalar spanning 2+ physical lines —
the style used by most skills/agents in this repo. scripts/vale-wrap.sh
flattens the description to one line in a scratch copy (preserving the
repo-relative path and total line count) before invoking real vale, and
both audit skills plus the pre-commit hook now call it instead of vale
directly. Also tightens the pre-commit hook's file glob to single path
segments so it can't cross into docs/research examples or asset
templates the way the audit skills' scoped invocations already avoid.

Addresses PR #85 review feedback.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FxG5T8EJDgkABXxuneuFfn

CONTEXT.md

@@ -70,7 +70,9 @@ A companion skill (`core` plugin) that detects a target repo's provider-specific
 A standalone, repo-agnostic plugin (`plugins/lint/`) for configuring and running linters — not scoped to kyberforge's own meta-tooling. First linter is Vale (prose style linting), split into two skills per the git/gitea per-concern pattern: `vale-config` (setup — `.vale.ini`, `StylesPath`, styles) and `vale-run` (invoke Vale, interpret/report findings). A `lint-runner` agent composes these for isolated-context lint sweeps; it is report-only (no `Edit` tool) — it flags findings, it does not rewrite prose. Vale's research docs (`docs/research/docs/vale/`) moved from `plugins/kyberforge/` to `plugins/lint/` to keep the provenance chain same-plugin.
 
 ### Vale audit prefilter (skill-audit / agent-audit)
-Wiring Vale as a deterministic prefilter for `skill-audit`/`agent-audit`'s Description dimension (ADR motivation: issue #84) is repo-specific, not part of the generic `lint` plugin, so its config lives at the repo root rather than inside `plugins/lint/`: `.vale.ini` plus a custom `Kyberforge` style (`styles/Kyberforge/`) covering description-opener banning ("This skill/agent..."), vague-capability wording ("helps with", "utilize", ...), and generic "see references/ for details" padding — and a `KyberforgeCopilot` style (`styles/KyberforgeCopilot/`) scoped only to `.agent.md` files for the Copilot-only "Use proactively has no effect" check. Both skills' Step 1 run `vale --config .vale.ini <target>` against the specific file(s) being audited (never a repo-wide sweep) — Vale's glob matching crosses directory boundaries (`plugins/*/agents/*.md` matches nested `docs/research/examples/**/agents/*.md` too), so scoping every invocation to a known target file/dir is what keeps research-example files out of the audit's lint pass rather than the glob pattern itself. `error` alerts map to FAIL, `warning`/`suggestion` map to SUGGESTION. Vale only replaces the specific pattern-matchable sub-checks named in issue #84 (imperative opener, vague filler, `Use proactively`, generic reference-pointer padding) — body discipline, near-miss exclusion strength, and control calibration stay LLM judgment per the issue's explicit non-goals.
+Wiring Vale as a deterministic prefilter for `skill-audit`/`agent-audit`'s Description dimension (ADR motivation: issue #84) is repo-specific, not part of the generic `lint` plugin, so its config lives at the repo root rather than inside `plugins/lint/`: `.vale.ini` plus a custom `Kyberforge` style (`styles/Kyberforge/`) covering description-opener banning ("This skill/agent..."), vague-capability wording ("helps with", "utilize", ...), and generic "see references/ for details" padding — and a `KyberforgeCopilot` style (`styles/KyberforgeCopilot/`) scoped only to `.agent.md` files for the Copilot-only "Use proactively has no effect" check. `error` alerts map to FAIL, `warning`/`suggestion` map to SUGGESTION. Vale only replaces the specific pattern-matchable sub-checks named in issue #84 (imperative opener, vague filler, `Use proactively`, generic reference-pointer padding) — body discipline, near-miss exclusion strength, and control calibration stay LLM judgment per the issue's explicit non-goals.
+
+Both skills' Step 1, and the `vale-audit-prefilter` pre-commit hook, call `scripts/vale-wrap.sh` rather than `vale` directly — a workaround for a confirmed Vale 3.15.2 limitation (see `vale-config`'s Gotchas): `text.frontmatter.description` silently stops matching once the description is a YAML block scalar (`>`/`|`) spanning 2+ physical lines, which is how most skills/agents in this repo write it. The wrapper flattens the description to one physical line in a scratch copy (padding with blank lines so every other line number is unchanged) before handing off to real `vale`; single-line descriptions pass through untouched. `tests/test-vale-wrap.sh` regression-tests this. Both call sites still scope every invocation to the specific file(s) being audited, never a repo-wide sweep — Vale's glob matching crosses directory boundaries (`plugins/*/agents/*.md` matches nested `docs/research/examples/**/agents/*.md` too), so scoping is what keeps research-example files out of the audit's lint pass. The pre-commit hook's own glob is tightened to `^plugins/[^/]+/(skills/[^/]+/SKILL\.md|agents/[^/]+\.md)$` (single-segment, not `.*`) for the same reason, since pre-commit invokes it automatically against whatever staged files match rather than a manually-scoped target.
 
 ### LESSONS.md
 Long-loop feedback log for patterns observed across sessions. Three or more entries on the same pattern graduate to the relevant standing file (e.g. a coding convention, a governance rule). Updated by the session-handoff skill or directly by the human. Lives at the repo root.