WIP: WASM port - switch to ncruces/go-sqlite3, add WASM stubs

- Switched from modernc.org/sqlite to ncruces/go-sqlite3 for WASM support
- Added WASM-specific stubs for daemon process management
- Created wasm/ directory with build.sh and Node.js runner
- WASM build succeeds (32MB bd.wasm)
- Node.js can load and execute the WASM module
- Next: Need to bridge Go file I/O to Node.js fs module

Related: bd-44d0, bd-8534, bd-c7eb

cmd/bd/daemon_lock_wasm.go

@@ -0,0 +1,14 @@
+//go:build js && wasm
+
+package main
+
+import (
+	"fmt"
+	"os"
+)
+
+func flockExclusive(f *os.File) error {
+	// WASM doesn't support file locking
+	// In a WASM environment, we're typically single-process anyway
+	return fmt.Errorf("file locking not supported in WASM")
+}

cmd/bd/daemon_wasm.go

@@ -0,0 +1,28 @@
+//go:build js && wasm
+
+package main
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+)
+
+// WASM doesn't support signals or process management
+var daemonSignals = []os.Signal{}
+
+func configureDaemonProcess(cmd *exec.Cmd) {
+	// No-op in WASM
+}
+
+func sendStopSignal(process *os.Process) error {
+	return fmt.Errorf("daemon operations not supported in WASM")
+}
+
+func isReloadSignal(sig os.Signal) bool {
+	return false
+}
+
+func isProcessRunning(pid int) bool {
+	return false
+}

cmd/bd/doctor.go

@@ -16,7 +16,8 @@ import (
 	"github.com/steveyegge/beads"
 	"github.com/steveyegge/beads/internal/configfile"
 	"github.com/steveyegge/beads/internal/daemon"
-	_ "modernc.org/sqlite"
+	_ "github.com/ncruces/go-sqlite3/driver"
+	_ "github.com/ncruces/go-sqlite3/embed"
 )
 
 // Status constants for doctor checks

cmd/bd/migrate.go

@@ -16,7 +16,8 @@ import (
 	"github.com/steveyegge/beads/internal/storage/sqlite"
 	"github.com/steveyegge/beads/internal/types"
 	"github.com/steveyegge/beads/internal/utils"
-	_ "modernc.org/sqlite"
+	_ "github.com/ncruces/go-sqlite3/driver"
+	_ "github.com/ncruces/go-sqlite3/embed"
 )
 
 var migrateCmd = &cobra.Command{