pipeline: EDITORIAL.md voice charter + fresh-eyes copy-edit stage

One written standard for every audience-facing word: concise, to the
point, inspiring delight through specificity — with word budgets per
copy type (reviews had drifted from a ~370-word median to 500-1000+).
All writing skills now reference the charter, and daily-pipeline gains
a stage-4 copy-edit pass: a subagent that didn't write the day's copy
tightens it against the charter, prose only, diff reviewed before
commit. Digest gains a copy-edit line.

Claude-Session: https://claude.ai/code/session_01WZaczDJjL3xZ3u5spsN5AL

.claude/skills/cluster-bundles/SKILL.md

@@ -89,7 +89,7 @@ items:
 
 Body rules (same as `build-bundle`):
 
-- 1-2 sentence intro paragraph in a blockquote. No headings, no list items, no numbered candidates — the grid handles the items.
+- 1-2 sentence intro paragraph in a blockquote, per `EDITORIAL.md`. No headings, no list items, no numbered candidates — the grid handles the items.
 - Audience-facing language. Never write "today's pick", "candidates", "winners".
 - Vary the opening across the batch. With 4-7 bundles going out the same day, repeating "Today's catch" five times feels mechanical.