chore: better error handling (#25)

* swarm: add revert_reason to transaction receipts for error observability

Propagate ErrorCode information from failed TxResult responses through
the receipt pipeline so Ethereum tooling (ethers, viem, Foundry) can
surface revert reasons via the revertReason field.

Changes:
- RpcReceipt: add optional revert_reason field (skip_serializing_if None)
- RpcReceipt::success(): set revert_reason: None
- RpcReceipt::failure(): accept revert_reason: Option<String> parameter
- StoredReceipt: add optional revert_reason field
- StoredReceipt::to_rpc_receipt(): pass through revert_reason
- SQLite receipts table: add revert_reason TEXT column
- insert_receipt(): include revert_reason in INSERT
- get_receipt() SELECT: include receipts.revert_reason (column index 12)
- row_to_stored_receipt(): read revert_reason at index 12
- build_stored_receipt(): format ErrorCode(id=0x{id:04x}, arg={arg}) on Err
- Test helpers updated with revert_reason: None

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* add more tests and clearer startup paths

* tests and stability

* comments and linting

* fixes

* fixes++

* ++

* ++

---------

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: tac0turtle

bin/testapp/examples/print_token_address.rs

@@ -0,0 +1,52 @@
+use std::path::PathBuf;
+use std::sync::mpsc;
+
+use clap::Parser;
+use commonware_runtime::tokio::{Config as TokioConfig, Runner};
+use commonware_runtime::Runner as RunnerTrait;
+use evolve_node::HasTokenAccountId;
+use evolve_server::load_chain_state;
+use evolve_storage::{QmdbStorage, StorageConfig};
+use evolve_testapp::GenesisAccounts;
+use evolve_tx_eth::derive_runtime_contract_address;
+
+#[derive(Debug, Parser)]
+#[command(name = "print_token_address")]
+#[command(about = "Print the testapp token contract address for an initialized data dir")]
+struct Cli {
+    /// Path to the initialized node data directory
+    #[arg(long)]
+    data_dir: PathBuf,
+}
+
+fn main() {
+    let cli = Cli::parse();
+    let data_dir = cli.data_dir;
+    let (tx, rx) = mpsc::channel();
+
+    let runtime_config = TokioConfig::default()
+        .with_storage_directory(&data_dir)
+        .with_worker_threads(2);
+
+    Runner::new(runtime_config).start(move |context| async move {
+        let storage = QmdbStorage::new(
+            context,
+            StorageConfig {
+                path: data_dir,
+                ..Default::default()
+            },
+        )
+        .await
+        .expect("open qmdb storage");
+
+        let state =
+            load_chain_state::<GenesisAccounts, _>(&storage).expect("load initialized chain state");
+        let token_address =
+            derive_runtime_contract_address(state.genesis_result.token_account_id());
+
+        tx.send(token_address).expect("send token address");
+    });
+
+    let token_address = rx.recv().expect("receive token address");
+    println!("{token_address:#x}");
+}

bin/testapp/src/genesis_config.rs

@@ -28,9 +28,29 @@ pub struct TokenConfig {
 #[derive(Deserialize)]
 pub struct AccountConfig {
     pub eth_address: String,
+    #[serde(deserialize_with = "deserialize_u128_balance")]
     pub balance: u128,
 }
 
+fn deserialize_u128_balance<'de, D>(deserializer: D) -> Result<u128, D::Error>
+where
+    D: serde::Deserializer<'de>,
+{
+    use serde::de::Error;
+
+    let value = serde_json::Value::deserialize(deserializer)?;
+    match value {
+        serde_json::Value::Number(number) => number
+            .to_string()
+            .parse::<u128>()
+            .map_err(|e| Error::custom(format!("invalid balance number: {e}"))),
+        serde_json::Value::String(text) => text
+            .parse::<u128>()
+            .map_err(|e| Error::custom(format!("invalid balance string: {e}"))),
+        _ => Err(Error::custom("expected balance as number or string")),
+    }
+}
+
 /// Persisted genesis result (replaces testapp's GenesisAccounts for evd).
 #[derive(Debug, Clone, Copy, BorshSerialize, BorshDeserialize)]
 pub struct EvdGenesisResult {