Add OrvexCL PancakeInfinity fork to Robinhood - #621

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

## Description

Adds fork integration tests for the OrvexCL (PancakeSwap Infinity fork)
integration on RobinHood:

- `test/integration/OrvexCL.t.sol`: `OrvexCLTest` harness targeting the
`robinhood` fork with the RobinHood settler flavors and the Orvex
vault/CL manager (`binPoolManager()` is `address(0)` since Orvex has no
Bin pool manager), plus a concrete WETH→NVDA pair test against the
deepest hookless Orvex CL pool
(`0x257df135116403937e4b04b22b796e6746d965090fef574b684c9c294c542490`,
fee 3000).
- `test/integration/PancakeInfinity.t.sol`: the harness previously
hardcoded the canonical PancakeSwap Infinity addresses; the vault and
pool manager addresses are now virtual functions
(`vault()`/`clPoolManager()`/`binPoolManager()`) defaulting to
canonical, so the existing Bnb pair tests are unchanged.
- `foundry.toml`: `robinhood` RPC endpoint alias.
- `.github/workflows/integration.yml`: passes
`ROBINHOOD_MAINNET_RPC_URL` to the integration test run.
- Gas snapshots for the new tests.

Covered paths, all executing real swaps through the Orvex vault lock →
settler callback → Orvex CL manager:

```
[PASS] testPancakeInfinity()                    taker-submitted, settler-held balance
[PASS] testPancakeInfinityVIP()                 Permit2 VIP
[PASS] testPancakeInfinityVIPAllowanceHolder()  AllowanceHolder
[PASS] testPancakeInfinityMetaTxn()             MetaTxn flavor
```

## ⚠️ Before merging

The `ROBINHOOD_MAINNET_RPC_URL` repository secret must be added,
otherwise the integration workflow cannot fork RobinHood and the new
tests will fail in CI.

🤖 Generated with [Claude Code](https://claude.com/claude-code)