feat(lint): expand Vale audit prefilter into a broader plugin-content harness

Deferred item from PR #85 review. Per ADR-0013: cherry-picks two low-noise
rules from trialing write-good/alex against the real corpus (VagueQualifier,
SentenceOpenerThereIs) into styles/Kyberforge rather than adopting either
package wholesale (both are tuned for blog prose and were noisy on this
repo's terse, imperative instruction files - see the ADR's rejected-rule
list). Adds a new skill-size-check pre-commit hook enforcing agentskills.io's
500-line/5,000-token SKILL.md ceiling, currently unenforced. Fixes the 28
resulting violations across 20 existing SKILL.md/agent files so the
enforcing pre-commit hook lands clean.

governance.md/CONTROLS.md were evaluated and excluded as rule sources -
they're org/CI-infrastructure controls, not prose patterns Vale can express.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QUDczvw1H3eEeMD29Q9Lbi

styles/Kyberforge/SentenceOpenerThereIs.yml

@@ -0,0 +1,7 @@
+extends: existence
+message: "Don't start a sentence with '%s' — name the subject directly"
+level: warning
+scope: text
+ignorecase: false
+raw:
+  - '(?:[;-]\s)There\s(is|are)|\bThere\s(is|are)\b'

styles/Kyberforge/VagueQualifier.yml

@@ -0,0 +1,36 @@
+extends: existence
+message: "'%s' is vague filler wording — state the point precisely instead"
+level: warning
+scope: text
+ignorecase: true
+tokens:
+  - clearly
+  - obviously
+  - obvious
+  - simply
+  - simple
+  - easily
+  - easy
+  - of course
+  - everyone knows
+  - completely
+  - exceedingly
+  - excellent
+  - extremely
+  - fairly
+  - huge
+  - interestingly
+  - largely
+  - mostly
+  - quite
+  - relatively
+  - remarkably
+  - several
+  - significantly
+  - substantially
+  - surprisingly
+  - tiny
+  - usually
+  - various
+  - vast
+  - very