feat: pro 612 add wrapper fork test path for polygon

[Seth-Schmidt]

Summary

Generalizes the Confidential Wrapper Foundry fork-test harness from Ethereum-only to multi-network, and adds Polygon as the second supported chain (PRO-612).

Core changes

Multi-network fork infrastructure

• Replaces resolve-fork.sh with fork-test.sh, which resolves the fork block and invokes forge test --fork-url <network>.
• Adds [rpc_endpoints] aliases in foundry.toml (ethereum, polygon).
• Moves per-network config into config/ethereum/ and config/polygon/.
• BaseForkTest reads the registry address from config/fork.json instead of a hardcoded constant.

Deny-list config consolidation

• Merges blacklist-seeds.json into blacklist-interfaces.json.
• Networks without deny-list-bearing underlyings omit the file; the deny-list suite skips itself.

Polygon support

• Adds Polygon registry and USDC deny-list config.
• Batcher suite skips on Polygon (no config/polygon/batchers.json).

Test changes

• Moves the zero-address deny-list exemption test from Foundry fork tests to ConfidentialWrapperV3.test.ts (wrap/unwrap when underlying denies address(0)).