fix(social-ugig): use current gig input schema

[WNZhao]

Problem

social-ugig still posts the legacy payload (content, tags, and price_cents). The current uGig POST /api/gigs contract requires skills_required, budget_type, and location_type, with fixed prices represented by budget_min / budget_max. Real non-dry-run publishing therefore receives a validation error instead of creating a gig.

The old adapter also leaves listing intent ambiguous, which can place a seller offer in the hiring feed.

Fix

• emit the current GigInput fields
• default social publishing to listing_type: for_hire, with an explicit hiring override
• map hashtags/default skills to required skills_required
• convert defaultPriceCents to dollar-valued fixed budgets
• support payment coin, duration, and preferred AI tools
• enforce uGig title/description minimums before the network request
• use the full current 5,000-character description limit
• redact the bearer token if an API error echoes it
• graduate the adapter from smoke coverage to the social contract suite

Verification

• pnpm exec vitest run packages/social/ugig/src/index.test.ts --reporter=dot — 8/8 passed
• pnpm --filter @profullstack/sh1pt-social-ugig typecheck — passed
• pnpm --filter @profullstack/sh1pt-social-ugig build — passed
• git diff --check — passed

The request fields and limits were checked against uGig's live /openapi.json; listing_type was additionally checked against the live create/edit UI payload and response model.