Production-grade rewrite: fix settlement, add safety, CI, multi-chain, SDK

## Contracts (BREAKING)
- Fix broken settlement logic: proper market resolution + winner/loser payouts
- Add ReentrancyGuard on withdraw/settlement, Pausable on deposit/orders
- Add order cancellation (cancelOrder), market resolution (resolveMarket)
- Add MIN_ORDER_SIZE (0.001 ETH) to prevent DoS via dust orders
- Losers get unmatched refund, winners get original + pro-rata of losing pool
- FlashGridFactory now accepts resolver address for each market

## Tests (800+ LOC)
- 45+ test cases including market resolution, payout correctness, edge cases
- Fuzz tests: settlement conservation, deposit/withdraw, balance consistency
- Reentrancy attack test with malicious contract
- Pause/unpause, min order size, order cancellation tests
- Stress test: 50 orders per tick settlement

## CI/CD
- GitHub Actions workflow: contracts (build, test, fuzz, fmt) + dashboard (typecheck, build) + SDK

## Multi-Chain
- New chains.ts config supporting Monad Testnet, Sepolia, Base Sepolia
- Refactored wallet.ts, indexer.ts, contract.ts to use dynamic chain config
- foundry.toml updated with Sepolia + Base Sepolia RPC endpoints

## SDK (@flashgrid/sdk)
- Standalone npm package with types, ABIs, chain config, and FlashGridClient class
- Full TypeScript SDK for deploying and interacting with FlashGrid markets

https://claude.ai/code/session_01AYqngFhM9R9jAN8zGzLGqk

Author: claude

.github/workflows/ci.yml

@@ -0,0 +1,90 @@
+name: CI
+
+on:
+  push:
+    branches: [main, "feature/**"]
+  pull_request:
+    branches: [main]
+
+jobs:
+  contracts:
+    name: Contracts (Build + Test + Fmt)
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: contracts
+
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          submodules: recursive
+
+      - name: Install Foundry
+        uses: foundry-rs/foundry-toolchain@v1
+
+      - name: Install dependencies
+        run: forge install
+
+      - name: Build contracts
+        run: forge build --sizes
+
+      - name: Run tests
+        run: forge test -vvv
+
+      - name: Run fuzz tests (extended)
+        run: forge test --match-test "testFuzz" -vvv --fuzz-runs 500
+
+      - name: Check formatting
+        run: forge fmt --check
+
+  dashboard:
+    name: Dashboard (Lint + Typecheck + Build)
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: dashboard
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: "20"
+          cache: npm
+          cache-dependency-path: dashboard/package-lock.json
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: TypeScript typecheck
+        run: npx tsc --noEmit
+
+      - name: Build
+        run: npm run build
+
+  sdk:
+    name: SDK (Typecheck + Build)
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: sdk
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: "20"
+          cache: npm
+          cache-dependency-path: sdk/package-lock.json
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: TypeScript typecheck
+        run: npx tsc --noEmit
+
+      - name: Build
+        run: npm run build

contracts/foundry.toml

@@ -10,8 +10,15 @@ optimizer_runs = 200
 line_length = 120
 tab_width = 4
 
+[profile.default.fuzz]
+runs = 256
+
 [rpc_endpoints]
 monad_testnet = "https://testnet-rpc.monad.xyz"
+sepolia = "${SEPOLIA_RPC_URL}"
+base_sepolia = "${BASE_SEPOLIA_RPC_URL}"
 
 [etherscan]
 monad_testnet = { key = "", url = "https://testnet.monadvision.com/api" }
+sepolia = { key = "${ETHERSCAN_API_KEY}", url = "https://api-sepolia.etherscan.io/api" }
+base_sepolia = { key = "${BASESCAN_API_KEY}", url = "https://api-sepolia.basescan.org/api" }

contracts/script/Deploy.s.sol

@@ -8,13 +8,14 @@ import {ParallelBenchmark} from "../src/ParallelBenchmark.sol";
 contract DeployScript is Script {
     function run() external {
         uint256 deployerPrivateKey = vm.envUint("PRIVATE_KEY");
+        address deployer = vm.addr(deployerPrivateKey);
         vm.startBroadcast(deployerPrivateKey);
 
         // 1. Deploy Factory
         FlashGridFactory factory = new FlashGridFactory();
         console2.log("FlashGridFactory deployed at:", address(factory));
 
-        // 2. Create default market via factory
+        // 2. Create default market (deployer is resolver)
         address market = factory.createMarket("Will MON reach $10 by Q2 2025?");
         console2.log("FlashGrid market deployed at:", market);
 
@@ -24,10 +25,10 @@ contract DeployScript is Script {
 
         vm.stopBroadcast();
 
-        // Output addresses for scripts
         console2.log("\n=== Deployment Summary ===");
         console2.log("Factory:   ", address(factory));
         console2.log("Market:    ", market);
+        console2.log("Resolver:  ", deployer);
         console2.log("Benchmark: ", address(benchmark));
         console2.log("Chain ID:  ", block.chainid);
     }