Season authoring operations

Create a season interactively or provide flags for repeatable automation:

pnpm season:create -- \
  --season-name "Countries" \
  --theme-name countries \
  --theme-family places \
  --difficulties easy,normal,hard \
  --start-date 2026-07-01 \
  --end-date 2026-08-04 \
  --word-file ./word-lists/countries.txt \
  --report-json ./reports/season.json

Then validate the configured season windows:

pnpm season:validate
pnpm content:validate
pnpm content:simulate -- --days=14 --from=2026-07-01 --theme=countries
pnpm runtime:status -- --as-of=2026-07-01

Validation failures usually come from malformed dates, overlapping windows, unknown themes, insufficient capacity, or editorial coverage gaps. Resolve the earliest structural failure first; later diagnostics may only be consequences.