Add migration step for new subheading column to deployment checklist

Update replit.md to include a SQL migration step for the new `kind` column in the `executive_meeting_attendees` table.

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replit.md

@@ -102,3 +102,5 @@
 ## Task #207 — Custom subheadings inside attendee cells (April 2026)
 
 `executive_meeting_attendees.kind` (`varchar(16) NOT NULL DEFAULT 'person'`) lets meetings interleave free-text section headers ("subheadings") with person rows. Subheadings are excluded from the running attendee number and from the per-meeting attendee count surface, but reorder/delete identically to person rows. The schema lives in `lib/db/src/schema/executive-meetings.ts`. All four insert paths (POST, PATCH attendees replace, PUT attendees, duplicate) round-trip `kind`. The PDF renderer (`artifacts/api-server/src/lib/pdf-renderer.ts`) prints subheadings as `— label —` and skips them when incrementing `personIdx`.
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+**Deployment / migration step (run once per environment before the next release):** the new `kind` column has `NOT NULL DEFAULT 'person'`, so existing rows are auto-backfilled by Postgres on add-column. Apply via either `pnpm --filter @workspace/db run push-force` (recommended; idempotent) or, if push is blocked by other legacy data in that environment, run this one-line SQL: `ALTER TABLE executive_meeting_attendees ADD COLUMN IF NOT EXISTS kind varchar(16) NOT NULL DEFAULT 'person';`. Verify backfill with `SELECT kind, COUNT(*) FROM executive_meeting_attendees GROUP BY kind;` — every existing row should report `kind = 'person'`.