22 tests covering the MariaDBBridge (C API wrapping, init/destroy
lifecycle, query execution, error handling) and the MySQL protocol
server (TCP handshake, COM_QUERY for SELECT and non-SELECT, COM_PING,
COM_QUIT, error packets, server shutdown).

The embedded server needs data directories in the Emscripten virtual
filesystem and specific startup flags (--skip-grant-tables, --datadir,
--default-storage-engine=MyISAM) to work without mysql_install_db.

The init() method now creates /usr/local/mysql/data in MEMFS, builds
the argv array for mysql_server_init, and passes the flags so the server
starts cleanly. This was tested end-to-end with the compiled WASM module
from github.com/adamziel/mariadb-wasm — CREATE DATABASE, CREATE TABLE,
INSERT, and SELECT all work correctly.

The MariaDB C API returns unsigned long long values for affected_rows,
insert_id, and field metadata (length, flags). Without WASM_BIGINT,
Emscripten truncates these to signed 32-bit, causing negative values
that crash Node.js Buffer operations.

The fix: clamp negative values to 0 for affected_rows/insert_id, and
use unsigned interpretation (>>> 0) for field metadata. The protocol
server's encodeLenEncInt also guards against negative inputs.

This was the final blocker for WordPress installation — with these
fixes, WordPress installs and runs successfully on MariaDB WASM.

MariaDB in WASM can't detect the Emscripten stack size, so
thread_stack defaults to 0 and large INSERT queries fail with
"Thread stack overrun." Setting it to 1MB fixes this.

Also suppress the "Can't open and lock privilege tables" warnings
that are expected when running with --skip-grant-tables.

The embedded server logged "Can't open and lock privilege tables"
because the mysql system database was empty — no tables existed.
This is the equivalent of never running mysql_install_db.

The init() method now creates the essential system tables
(global_priv, plugin, servers, func, proc) with a root user that
has all privileges. This eliminates the privilege table warnings.

Also set --thread-stack=1048576 because Emscripten can't detect
the WASM stack size, so MariaDB defaults thread_stack to 0 and
rejects large INSERT queries with "Thread stack overrun."

Instead of disabling 64-bit integers globally (WASM_BIGINT=0), keep
proper 64-bit support and convert BigInt to Number at the bridge
boundary. mysql_affected_rows and mysql_insert_id return unsigned
long long which becomes BigInt with WASM_BIGINT=1 — the wrapBigInt
helper converts these to plain Numbers for downstream use in Buffer
operations and the MySQL wire protocol encoder.

Instead of keeping MariaDB data in Emscripten's volatile MEMFS, mount
a real host directory at the data path. The CLI creates a mariadb-data
subdir inside the shared temp directory (alongside wordpress/, tmp/,
home/) and passes it to loadMariaDBModule. The bridge mounts it via
NODEFS before mysql_server_init so all MyISAM table files (.MYD, .MYI,
.frm) land on the real filesystem.

This reuses the same temp dir infrastructure the CLI already uses for
PHP's shared directories — no new flags needed.

Brings the mariadb-wasm build into the monorepo as a first-class
package. The build.sh script compiles MariaDB 11.4 to WebAssembly
via Emscripten with all the WASM-specific patches (Aria, timers,
curses, PCRE2 toolchain, servers_init). Pre-built dist/mariadb.js
and dist/mariadb.wasm are committed so consumers don't need the
Emscripten toolchain.

The CLI now defaults to the in-repo module when --database=mariadb
is used, so --mariadb-wasm-module is optional. Running WordPress on
MariaDB is now just:

  npx nx dev playground-cli -- server --database=mariadb

Lint fixes:
- Add eslint-disable for @nx/enforce-module-boundaries in vite.config.ts
- Remove unused variables in test mocks
- Use import type for MariaDBBridge in protocol server spec

Review feedback:
- Free WASM heap allocations for argv after mysql_server_init
- Escape backticks in database names to prevent SQL injection
- Track active sockets and destroy them on server shutdown
- Store MariaDBBridge reference and call destroy() on CLI exit

Also updates package-lock.json for the two new workspace packages.

The test-built-npm-packages CI job runs package-for-self-hosting
on all packages. Without this target, @wp-playground/mariadb wasn't
published to the local test registry, causing a 404 when the CLI
package tried to resolve it as a dependency.