skills/book-gig: surface granular seasonal hold and spacing status badges in reports and HTML artifacts

[JoshuaVSherman]

Child of web-jam-tools#875 ("book-gig skill phase 2 enhancements (Epic)").

What this builds

Enhances candidate preview tables, run logs, and HTML review artifacts to surface granular status badges and explicit exclusion reasoning for venues filtered by seasonal cooldowns, active direct conversations, or past gig spacing.

1. Updates filterAndRankCandidates in src/book-gig/candidates.ts and src/book-gig/html.ts to identify and badge specific eligibility states:
   • [Seasonal Hold: Jan 2027] for venues with active resumeBooking in the future.
   • [Gig Spacing: <Date> Show] for venues excluded by the ±2 month gig window.
   • [Direct Chat Active] for venues temporarily paused (outreachEligible: false with active direct conversation notes).
   • [Cooldown Active: Sent <Date>] for venues pitched within the 7-day cooldown window.
2. Updates renderCandidateTable and renderDarkHtml to display these colored badges in both terminal and Chrome review interfaces.
3. Adds unit tests in test/book_gig.test.ts verifying badge generation and reasoning output.

Acceptance criteria

1. Terminal table and HTML review artifact display granular reason badges for excluded/held venues.
2. deno task test, deno task fmt:check, deno task lint, and deno task sast pass 100% green.