feat: resolve rollup address from Aztec Registry, drop static config

[koenmtb1]

Summary

• Indexer: indexes Aztec Registry CanonicalRollupUpdated events into a new rollup_version table, and uses Ponder's factory pattern on the same event to auto-index every canonical rollup, historical, current, and future upgrades without a config change.
• New endpoint: GET /api/rollups returns current canonical + full history ([{version, address, blockNumber, timestamp}, ...]). Source of truth is the indexed table; served by a trivial select.
• API handlers: getCanonicalRollupAddress now reads the DB table first and only falls back to live Registry RPC during the brief pre-sync window.
• Frontend: resolves the rollup via fetch(${VITE_API_HOST}/api/rollups) at boot, no viem, no RPC dependency, no Registry ABI. Caches the full version list in getRollupVersions().
• Config: replaces ROLLUP_ADDRESS with REGISTRY_ADDRESS + REGISTRY_START_BLOCK on the indexer; drops VITE_ROLLUP_ADDRESS entirely on the frontend

Why

Rollup cutovers (Registry.addRollup()) change the canonical rollup's address. Previously that address was baked into env vars / CI secrets / Terraform, so every upgrade required a coordinated redeploy of both services. The Aztec Registry already exposes this via getCanonicalRollup() and emits CanonicalRollupUpdated on every upgrade.

After this change: upgrades are picked up automatically. The indexer keeps indexing events from every historical rollup forever (claims / withdrawal finalizations on old rollups continue flowing through existing handlers), and the frontend reads the current rollup on every page load.

Scope note

This PR makes the dashboard upgrade-aware for normal operation against the current canonical rollup. It does not yet let users claim rewards or finalize withdrawals against old rollups — the event data is preserved (rollupAddress is on every event in the schema), but the UI still issues claim/finalize transactions against the current canonical rollup only. This will follow in a follow-up PR.

Mainnet config values

• Registry address: 0x35b22e09Ee0390539439E24f06Da43D83f90e298
• Registry deployment block: 23786827
• Current canonical rollup (verified): 0xAe2001f7e21d5EcABf6234E9FDd1E76F50F74962
• numberOfVersions(): 2, factory backfill will replay both

Deploy checklist

• Add REGISTRY_ADDRESS + REGISTRY_DEPLOYMENT_BLOCK as GitHub environment vars for testnet and prod (both indexer + dashboard environments).
• After merge, ROLLUP_ADDRESS GH env var can be removed.
• Indexer re-sync required: the Rollup contract changed from a static address to factory-sourced, which invalidates the Ponder schema hash. Re-syncs from REGISTRY_START_BLOCK (~ATP factory deployment).
• Any contract_addresses.json files held outside the repo need registryAddress + registryDeploymentBlock added and rollupAddress removed.