Update all StoryFactory references to new contract address

[realproject7]

Summary

Replace all references to the old StoryFactory address with the new redeployed contract address across the plotlink web app codebase.

Files to update

• `lib/contracts/constants.ts` — `STORY_FACTORY` address and `DEPLOYMENT_BLOCK`
• `packages/sdk/src/constants.ts` — address + block (if exists)
• `.env.example` / `.env.local` — `NEXT_PUBLIC_CONTRACT_ADDRESS`
• Any hardcoded references to old address `0x337c5b96f03fB335b433291695A4171fd5dED8B0`

Also

• Initialize `backfill_cursor` in Supabase with new deployment block number
• Old storylines from the previous factory will no longer appear (different contract_address filter)

Reference

See contract redeploy checklist in memory for full list of steps.

Acceptance Criteria

• All references to old StoryFactory address replaced
• DEPLOYMENT_BLOCK updated
• backfill_cursor initialized for new contract
• No remaining references to old contract address