Released SQLite wpdb facade is incompatible with canonical MDI query results #162

Problem

MDI v0.8.8 now loads successfully with Studio SQLite Integration 3.0.0-rc.6, but the canonical driver migration in #150 changed WP_Markdown_Driver::query() to return PDOStatement. The released WP_SQLite_DB still consumes the deprecated facade contract:

• SELECT queries must return fetched row arrays.
• DML queries must expose get_last_return_value().
• WP_SQLite_DB::query() uses those values to populate last_result, num_rows, and rows_affected.

Live bootstrap now reaches init and fatals:

Fatal error: Call to undefined method WP_Markdown_Driver::get_last_return_value()
.../sqlite-database-integration/wp-includes/sqlite/class-wp-sqlite-db.php:438

Before init, WordPress also reports the site as uninstalled because SELECT statements are not materialized into the array shape that released WP_SQLite_DB expects.

Expected

MDI should preserve canonical PDO internals while adapting query results to the released WP_SQLite_DB facade when running against the pre-rename WP_PDO_MySQL_On_SQLite class. The renamed trunk path must retain PDO statement behavior. Coverage must prove SELECT rows, DML affected-row values, and MDI internal callers across both surfaces.

Evidence

• MDI v0.8.8 released and deployed
• SQLite Integration 3.0.0-rc.6
• Active previous drop-in now passes class loading through the v0.8.8 alias
• studio wp core is-installed --debug captures the get_last_return_value() fatal
• Released WP_SQLite_DB reads get_last_return_value() at line 438 and only recognizes array SELECT results at lines 450-453