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

wasm/build.sh

@@ -0,0 +1,10 @@
+#!/bin/bash
+# Build bd for WebAssembly
+
+set -e
+
+echo "Building bd for WASM..."
+GOOS=js GOARCH=wasm go build -o wasm/bd.wasm ./cmd/bd
+
+echo "WASM build complete: wasm/bd.wasm"
+ls -lh wasm/bd.wasm