fix(anchor-evm): address PR review comments and add full integration test

Fixes from PR #742 review:
- Fix tx_hash_to_cid: wrap hash with Keccak256 code + ETH_TX codec (0x93)
  instead of re-hashing with SHA2-256
- Fix AnchorProof parameter order: (chain_id, root, tx_hash, tx_type)
- Add chain ID validation after connecting to provider
- Implement retry logic with exponential backoff
- Add wallet balance logging for gas cost tracking
- Update default confirmations from 1 to 4 (matching JS implementation)

Code cleanup:
- Remove unused GasConfig (alloy handles gas estimation automatically)
- Remove unused get_root_block function and getRootBlock interface
- Consolidate gnosis_test.rs into integration_test.rs

Testing:
- Add test_cid_to_bytes32_matches_js to verify JS compatibility
- Add test_tx_hash_to_cid_matches_js to verify JS compatibility
- Add test_anchor_service_with_evm for full AnchorService flow testing
  (merkle tree building, EVM anchoring, time event creation)

Documentation:
- Update README with comprehensive test documentation
- Document all environment variables for integration tests
- Update contract interface to match actual implementation

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

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

Author: smrz2001

Cargo.lock

@@ -17,13 +17,13 @@ ceramic-core.workspace = true
 ceramic-event.workspace = true
 hex.workspace = true
 multihash-codetable.workspace = true
-serde.workspace = true
 tokio.workspace = true
 tracing.workspace = true
 url.workspace = true
 
 [dev-dependencies]
+ceramic-sql.workspace = true
 cid.workspace = true
 expect-test.workspace = true
 test-log.workspace = true
-tracing-subscriber.workspace = true
+tracing-subscriber.workspace = true

anchor-evm/Cargo.toml

@@ -4,85 +4,124 @@ A complete self-anchoring solution for Ceramic that can submit root CIDs to any
 
 ## Features
 
-- ✅ **Multi-chain Support**: Works with any EVM blockchain (Ethereum, Gnosis, Polygon, Arbitrum, Base, etc.)
-- ✅ **Production Ready**: Comprehensive error handling, retry logic, and gas management
-- ✅ **Compatible**: Maintains compatibility with existing Ceramic anchor service patterns
-- ✅ **Efficient**: Uses modern alloy library with optimal gas usage
-- ✅ **Self-Sovereign**: No reliance on centralized anchor services
+- **Multi-chain Support**: Works with any EVM blockchain (Ethereum, Gnosis, Polygon, Arbitrum, Base, etc.)
+- **Production Ready**: Comprehensive error handling, retry logic with exponential backoff
+- **Compatible**: Maintains compatibility with existing Ceramic anchor service patterns
+- **Efficient**: Uses modern alloy library with automatic gas estimation
+- **Self-Sovereign**: No reliance on centralized anchor services
 
-## Quick Test on Gnosis Chain
+## Testing
 
-The implementation includes a ready-to-test setup using Gnosis Chain with a deployed test contract.
+The crate includes comprehensive tests at multiple levels:
 
-### Prerequisites
+### Unit Tests (no blockchain required)
 
-1. **Test Account**: You'll need a test account with some xDAI (~0.01 xDAI for testing)
-2. **Private Key**: Export your test account's private key (hex format, no 0x prefix)
+```bash
+cargo test -p ceramic-anchor-evm
+```
+
+Runs 15 tests including:
+- CID to bytes32 conversion (verified against JS implementation)
+- Transaction hash to CID (uses Keccak256 multihash + ETH_TX codec)
+- Proof building with correct parameter order
+- Configuration validation
 
-### Running the Test
+### Integration Test: TransactionManager
+
+Tests the EVM transaction submission flow in isolation.
 
 ```bash
-# Set your test account private key
-export TEST_PRIVATE_KEY="your_private_key_hex_no_0x_prefix"
+# Required: Private key (hex, no 0x prefix)
+export TEST_PRIVATE_KEY="your_private_key_hex"
+
+# Optional: Override defaults
+export TEST_RPC_URL="https://gnosis-mainnet.g.alchemy.com/v2/YOUR_KEY"
+export TEST_CONTRACT_ADDRESS="0x231055A0852D67C7107Ad0d0DFeab60278fE6AdC"
+export TEST_CHAIN_ID="100"
 
-# Run the Gnosis anchoring test
-cd /Users/mz/Documents/3Box/GitHub/3box/rust-ceramic
-cargo test -p ceramic-anchor-evm test_gnosis_anchoring -- --ignored --nocapture
+# Run the test
+cargo test -p ceramic-anchor-evm test_evm_anchoring -- --ignored --nocapture
 ```
 
-### What the Test Does
+**What it tests:**
+1. Connects to EVM chain and validates chain ID
+2. Submits anchor transaction to contract
+3. Waits for confirmations
+4. Returns `RootTimeEvent` with correct proof structure
 
-1. **Configuration**: Sets up connection to Gnosis Chain via Alchemy RPC
-2. **Contract**: Uses deployed test contract at `0x231055A0852D67C7107Ad0d0DFeab60278fE6AdC`
-3. **CID Processing**: Converts a test Ceramic CID to the contract format
-4. **Transaction**: Submits anchoring transaction to the blockchain
-5. **Confirmation**: Waits for confirmations and validates the result
-6. **Verification**: Ensures the proof structure is correct for Ceramic
+### Integration Test: Full AnchorService Flow
 
-### Expected Output
+Tests the complete anchor pipeline including merkle tree building and time event creation.
 
+```bash
+export TEST_PRIVATE_KEY="your_private_key_hex"
+
+cargo test -p ceramic-anchor-evm test_anchor_service_with_evm -- --ignored --nocapture
 ```
-🧪 Testing EVM anchoring on Gnosis Chain
-📡 RPC: https://gnosis-mainnet.public.blastapi.io
-🔗 Chain ID: 100
-📄 Contract: 0x231055A0852D67C7107Ad0d0DFeab60278fE6AdC
-⏰ Confirmations: 2
-🔍 Validating configuration...
-✅ Configuration valid
-🏗️ Creating EVM transaction manager...
-✅ Transaction manager created
-📝 Test root CID: bafyreia776z4jdg5zgycivcpr3q6lcu6llfowkrljkmq3bex2k5hkzat54
-🔢 CID as bytes32: 0x1fffb3c48cddc9b024544f8ee1e58a9e5acaeb2a2b4a990d8497d2ba756413ef
-⚓ Starting anchoring process...
-🎉 Anchoring successful in 15.2s!
-📊 Results:
-  ├─ Chain ID: eip155:100
-  ├─ Transaction Type: f(bytes32)
-  ├─ Transaction Hash: bafkreifx4bqkmc5xvaxvg2ttyf554n5bw3hvo2pojkbslp7xnrk2sw3kuq
-  ├─ Proof CID: bafkreia...
-  └─ Path: ''
-✅ All verification checks passed!
-🔗 View transaction on Gnosis block explorer:
-   https://gnosisscan.io/tx/0x...
+
+**What it tests:**
+1. Creates mock anchor requests via `MockAnchorEventService`
+2. `AnchorService` builds merkle tree from requests
+3. Root CID is anchored on EVM chain
+4. Time events are created with correct merkle paths
+
+**Expected output:**
+```
+=== Full AnchorService Integration Test ===
+RPC: https://gnosis-mainnet.public.blastapi.io
+Chain ID: 100
+Contract: 0x231055A0852D67C7107Ad0d0DFeab60278fE6AdC
+Anchor requests: 3
+  Request 0: id=..., prev=...
+  Request 1: id=..., prev=...
+  Request 2: id=..., prev=...
+
+Anchoring batch...
+Anchoring completed in 18.64s
+
+=== Results ===
+Time events created: 3
+Proof chain ID: eip155:100
+Proof tx_type: f(bytes32)
+Proof tx_hash: bagjqcgza...
+Proof root: bafyreien...
+
+Time Event 0:
+  prev: baeabeig...
+  proof: bafyreic...
+  path: 0/0
+
+Time Event 1:
+  prev: baeabeig...
+  proof: bafyreic...
+  path: 0/1
+
+Time Event 2:
+  prev: baeabeig...
+  proof: bafyreic...
+  path: 1
+
+All assertions passed!
 ```
 
+### Test Prerequisites
+
+1. **Test Account**: You'll need a test account with some xDAI (~0.01 xDAI for testing)
+2. **Private Key**: Export your test account's private key (hex format, no 0x prefix)
+3. **Contract**: Default uses deployed test contract at `0x231055A0852D67C7107Ad0d0DFeab60278fE6AdC`
+
 ## Configuration
 
 The implementation supports comprehensive configuration for different networks:
 
 ```rust
-use ceramic_anchor_evm::{EvmConfig, GasConfig, RetryConfig};
+use ceramic_anchor_evm::{EvmConfig, RetryConfig};
 
 let config = EvmConfig {
     rpc_url: "https://gnosis-mainnet.g.alchemy.com/v2/YOUR_KEY".to_string(),
     private_key: "your_private_key_hex".to_string(),
     chain_id: 100, // Gnosis Chain
     contract_address: "0x231055A0852D67C7107Ad0d0DFeab60278fE6AdC".to_string(),
-    gas_config: GasConfig {
-        gas_limit: Some(300_000),
-        gas_increase_percent: 25, // 25% increase per retry
-        ..GasConfig::default()
-    },
     retry_config: RetryConfig {
         max_retries: 5,
         base_delay: Duration::from_secs(3),
@@ -137,16 +176,17 @@ Extremely cost-effective on Gnosis Chain:
 The implementation uses a simple, efficient contract interface:
 
 ```solidity
-contract SimpleAnchor {
-    mapping(bytes32 => uint256) public rootBlocks;
-    
+interface IAnchorContract {
+    /// Anchor a root CID on the blockchain
     function anchorDagCbor(bytes32 root) external;
-    function getRootBlock(bytes32 root) external view returns (uint256);
-    
+
+    /// Event emitted when a root is anchored
     event RootAnchored(bytes32 indexed root, uint256 blockNumber, address indexed anchor);
 }
 ```
 
+The contract only needs a single function - the Rust implementation handles all proof construction from the transaction receipt.
+
 ## Performance
 
 - **CID Processing**: 2M+ CIDs/second

anchor-evm/README.md

@@ -1,25 +1,18 @@
 use alloy::{
-    primitives::{Address, FixedBytes, U256},
+    primitives::{Address, FixedBytes},
     providers::Provider,
     sol,
     transports::Transport,
 };
 use anyhow::Result;
 
 // Solidity contract interface for anchoring Ceramic roots
-// Based on the existing CeramicAnchorServiceV2 pattern
 sol! {
     #[derive(Debug)]
     #[sol(rpc)]
     interface IAnchorContract {
-        /// Anchor a root CID on the blockchain (matching existing pattern)
+        /// Anchor a root CID on the blockchain
         function anchorDagCbor(bytes32 root) external;
-        
-        /// Get the block number when a root was anchored
-        function getRootBlock(bytes32 root) external view returns (uint256 blockNumber);
-        
-        /// Event emitted when a root is successfully anchored
-        event RootAnchored(bytes32 indexed root, uint256 blockNumber, address indexed anchor);
     }
 }
 
@@ -36,15 +29,12 @@ impl<T: Transport + Clone, P: Provider<T> + Clone> AnchorContract<T, P> {
     }
 
     /// Anchor a root CID on the blockchain
-    pub async fn anchor_root(&self, root: FixedBytes<32>) -> Result<alloy::rpc::types::TransactionReceipt> {
+    pub async fn anchor_root(
+        &self,
+        root: FixedBytes<32>,
+    ) -> Result<alloy::rpc::types::TransactionReceipt> {
         let call = self.contract.anchorDagCbor(root);
         let receipt = call.send().await?.get_receipt().await?;
         Ok(receipt)
     }
-
-    /// Check if a root has been anchored and return the block number
-    pub async fn get_root_block(&self, root: FixedBytes<32>) -> Result<U256> {
-        let result = self.contract.getRootBlock(root).call().await?;
-        Ok(result.blockNumber)
-    }
-}
+}