Interact-contract demo uses stale block heights and aborts on current mainnet

[Mosas2000]

The scripts/interact-contract.ts demo script still uses fixed block heights that were current in January 2026.

Evidence:

• scripts/interact-contract.ts:53-59 hardcodes END_BLOCK_HEIGHT = 6043000 and RESOLUTION_BLOCK_HEIGHT = 6043500.
• The script also hardcodes a fallback height of 6037876 at scripts/interact-contract.ts:42-45.
• Hiro mainnet now reports a much higher tip height (7604235 at the time of verification), so the script exits its own validation checks before it can submit any transactions.

Impact:

• The demo script is no longer runnable on current mainnet.
• Anyone following the example flow will hit the "END_BLOCK_HEIGHT is in the past" error immediately.

Reproduction:

1. Run npm run interact.
2. The script fetches the current block height.
3. It aborts because the hardcoded end/resolution blocks are already in the past.

Priority: High

Suggested scope:
Make the example script derive future blocks dynamically, or clearly mark it as outdated and non-production sample code.