fix: set PRAGMA busy_timeout=500 + SpendingLock on relinquishOutput

Same fix as bsv-wallet-cli main: SQLite contention caused ~11% of
relinquishOutput calls to fail with SQLITE_BUSY (error 517).

Root cause: busy_timeout=0 (instant failure) + relinquishOutput
running without SpendingLock (racing with createAction writes).

Fix: busy_timeout=500ms on both connections + SpendingLock guard
on relinquishOutput. Verified: 0% failure rate after fix.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: Calgooon

src/commands/daemon.rs

@@ -4,6 +4,7 @@ use bsv_sdk::wallet::{ListOutputsArgs, WalletInterface};
 use bsv_wallet_toolbox::{
     Chain, Monitor, Services, ServicesOptions, StorageSqlx, Wallet, WalletStorageWriter,
 };
+use sqlx::Executor;
 use std::sync::Arc;
 
 use crate::cli::Cli;
@@ -22,6 +23,12 @@ pub async fn run(cli: &Cli) -> Result<()> {
 
     let storage = StorageSqlx::open(&cli.db).await?;
     storage.make_available().await?;
+    // Set busy_timeout so concurrent writes wait instead of returning SQLITE_BUSY.
+    // Without this, relinquishOutput racing with createAction gets error 517 instantly.
+    sqlx::query("PRAGMA busy_timeout = 500")
+        .execute(storage.pool())
+        .await
+        .ok();
 
     let make_services = |chain: Chain| -> anyhow::Result<Services> {
         let mut opts = match chain {
@@ -51,6 +58,10 @@ pub async fn run(cli: &Cli) -> Result<()> {
     // so we need to create a separate storage/services for the wallet)
     let storage2 = StorageSqlx::open(&cli.db).await?;
     storage2.make_available().await?;
+    sqlx::query("PRAGMA busy_timeout = 500")
+        .execute(storage2.pool())
+        .await
+        .ok();
     let services2 = make_services(chain)?;
     let wallet = Wallet::new(Some(root_key), storage2, services2)
         .await

src/server/handlers.rs

@@ -707,12 +707,17 @@ pub async fn list_outputs(
 }
 
 /// POST /relinquishOutput
+///
+/// Acquires SpendingLock because relinquish modifies UTXO state and can race
+/// with createAction on SQLite writes (previously caused SQLITE_BUSY errors).
 pub async fn relinquish_output(
     State(wallet): State<WalletState>,
+    axum::Extension(spending_lock): axum::Extension<super::SpendingLock>,
     headers: HeaderMap,
     Json(args): Json<RelinquishOutputArgs>,
 ) -> Result<Json<RelinquishOutputResult>, AppError> {
     let originator = extract_originator(&headers)?;
+    let _guard = spending_lock.lock().await;
     let result = wallet
         .relinquish_output(args, &originator)
         .await