Add Solidity linting with solhint, Foundry formatter, and pre-commit hooks

- Added .solhint.json with recommended rules + custom config
  - 160 char line length (warn)
  - Double quotes enforcement (error)
  - Explicit visibility required (error)
  - Console statements allowed (scripts/tests need them)
  - Gas optimization warnings enabled
  - Ignores test/helpers/, lib/, out/, cache/, broadcast/

- Added foundry.toml [fmt] section
  - 160 char line length
  - 4-space tabs
  - Double quotes
  - Thousands separators for numbers
  - Sort imports enabled

- Added .lintstagedrc.json for pre-commit auto-fix
  - Runs solhint --fix on .sol files
  - Runs forge fmt on .sol files

- Added husky pre-commit hook via lint-staged

- lint:sol - run solhint
- lint:sol:fix - auto-fix solhint issues
- format:sol - format with forge fmt
- format:sol:check - check formatting
- lint / lint:fix - combined commands

- Added explicit visibility modifiers (internal) to constants in scripts and tests
- Fixed quote style in DeployLocal.sol
- All Solidity files formatted with forge fmt

- ✅ forge fmt --check passes
- ✅ No solhint errors (warnings only)
- ✅ forge build succeeds
- ✅ forge test passes (107/107)

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

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

onchain/script/DeployScript2.sol

@@ -1,25 +1,26 @@
 pragma solidity ^0.8.19;
 
-import "forge-std/Script.sol";
+import "../src/Kraiken.sol";
+
+import { LiquidityManager } from "../src/LiquidityManager.sol";
+import "../src/Optimizer.sol";
+import "../src/Stake.sol";
+import "../src/helpers/UniswapHelpers.sol";
+import { ERC1967Proxy } from "@openzeppelin/proxy/ERC1967/ERC1967Proxy.sol";
 import "@uniswap-v3-core/interfaces/IUniswapV3Factory.sol";
 import "@uniswap-v3-core/interfaces/IUniswapV3Pool.sol";
-import "../src/Kraiken.sol";
-import "../src/Stake.sol";
-import "../src/Optimizer.sol";
-import "../src/helpers/UniswapHelpers.sol";
-import {LiquidityManager} from "../src/LiquidityManager.sol";
-import {ERC1967Proxy} from "@openzeppelin/proxy/ERC1967/ERC1967Proxy.sol";
+import "forge-std/Script.sol";
 
 uint24 constant FEE = uint24(10_000);
 
 contract DeployScript is Script {
     using UniswapHelpers for IUniswapV3Pool;
 
-    bool token0isWeth;
-    address feeDest;
-    address weth;
-    address v3Factory;
-    address twabc;
+    bool internal token0isWeth;
+    address internal feeDest;
+    address internal weth;
+    address internal v3Factory;
+    address internal twabc;
 
     function run() public {
         string memory seedPhrase = vm.readFile(".secret");