chore: update contract verification default to Cancun

CLAUDE.md

@@ -143,7 +143,7 @@ Admin commands via `indexer_state` table: rescan from height, retry failed block
 Refreshes `daily_stats` table after each batch.
 
 ## QFC-Specific Notes
-- **EVM version**: QFC does NOT support PUSH0. Always `evmVersion: "paris"`.
+- **EVM version**: QFC runs Cancun spec. Default `evmVersion: "cancun"`. Supports PUSH0, MCOPY, TSTORE/TLOAD.
 - **eth_call quirk**: QFC testnet may return `0x` for view functions. Use `eth_getStorageAt` as workaround.
 - **Proxy detection**: Reads EIP-1967/1822/Beacon storage slots to identify proxy contracts.
 - **Custom RPC methods**: `qfc_getEpoch`, `qfc_getValidators`, `qfc_getNodeInfo`, `qfc_getInferenceStats`, `qfc_getSupportedModels`, etc.

src/lib/vyper-compiler.ts

@@ -33,7 +33,7 @@ function exec(cmd: string, args: string[], timeout = 60_000): Promise<{ stdout:
 export async function compileVyper(
   source: string,
   version: string,
-  evmVersion: string = 'paris',
+  evmVersion: string = 'cancun',
 ): Promise<VyperCompileResult | VyperCompileError> {
   const tmpDir = await mkdtemp(join(tmpdir(), 'vyper-'));
   const srcPath = join(tmpDir, 'contract.vy');

src/routes/contracts.ts

@@ -400,7 +400,7 @@ export default async function contractsRoutes(app: FastifyInstance) {
       // Dynamic import solc (optional dependency)
       // eslint-disable-next-line @typescript-eslint/no-require-imports
       const solc = await import(/* webpackIgnore: true */ 'solc' as string) as { compile: (input: string) => string };
-      const evmVersion = body.evmVersion || 'paris';
+      const evmVersion = body.evmVersion || 'cancun';
       const input = JSON.stringify({
         language: 'Solidity',
         sources: { 'contract.sol': { content: body.sourceCode } },
@@ -506,8 +506,8 @@ export default async function contractsRoutes(app: FastifyInstance) {
       // Ensure output selection includes what we need
       if (!jsonInput.settings) jsonInput.settings = {};
       jsonInput.settings.outputSelection = { '*': { '*': ['abi', 'evm.bytecode', 'evm.deployedBytecode'] } };
-      // QFC: always paris
-      if (!jsonInput.settings.evmVersion) jsonInput.settings.evmVersion = 'paris';
+      // QFC: default to cancun
+      if (!jsonInput.settings.evmVersion) jsonInput.settings.evmVersion = 'cancun';
 
       const solc = await import(/* webpackIgnore: true */ 'solc' as string) as { compile: (input: string) => string };
       const output = JSON.parse(solc.compile(JSON.stringify(jsonInput)));
@@ -617,7 +617,7 @@ export default async function contractsRoutes(app: FastifyInstance) {
 
     try {
       const solc = await import(/* webpackIgnore: true */ 'solc' as string) as { compile: (input: string) => string };
-      const evmVersion = body.evm_version || 'paris';
+      const evmVersion = body.evm_version || 'cancun';
       const optimizationRuns = body.optimization_runs ?? null;
 
       // Build Solidity Standard JSON Input from multi-file sources
@@ -764,7 +764,7 @@ export default async function contractsRoutes(app: FastifyInstance) {
     }
 
     try {
-      const evmVersion = body.evm_version || 'paris';
+      const evmVersion = body.evm_version || 'cancun';
       const result = await compileVyper(body.source_code, body.compiler_version, evmVersion);
 
       if ('error' in result) {

src/routes/etherscan.ts

@@ -599,8 +599,8 @@ async function handleVerifySourceCode(params: Record<string, string>): Promise<E
   const optimizationUsed = params.optimizationUsed || params.optimizationused || '0';
   const runs = parseInt(params.runs || '200', 10);
   const constructorArgs = params.constructorArguements || params.constructorarguments || '';
-  // QFC does NOT support PUSH0 — always force paris
-  const evmVersion = 'paris';
+  // QFC EVM runs Cancun spec (PUSH0, MCOPY, TSTORE/TLOAD supported)
+  const evmVersion = 'cancun';
 
   // Fetch deployed bytecode from chain
   const deployedCode = await rpcCallSafe<string>('eth_getCode', [address, 'latest']);