fix(mcp): run beside the mcp adapter 0.7.0 instead of fatalling (#340)

[ifahimreza]

Closes #340. Follow-up for full 0.7.0 support: #341

The bug

MCP Adapter 0.7.0 (2026-10-02) took down any Saddle site that installed it:

1. Activation fatal (builds with the bundled adapter): Cannot declare class WP\MCP\Autoloader. The bundle was already loaded; the plugin's require_once is a different path.
2. Every request fatal (every build, including WordPress.org 1.5.0): Too few arguments to McpServer::get_tools(). 0.7.0 made get_tools(), get_resources() and get_prompts() require the request's protocol schema; Saddle called them bare in record_server_health() and filter_adapter_initialize().
3. Right after deactivating the adapter, one more request could fatal: the bundle's Jetpack Autoloader picked the inactive plugin's newer classes from its cache.

The fix

• Saddle_Bundled_Adapter::standalone_installed(): with an official plugin folder present (mcp-adapter*/mcp-adapter.php, active or not), the bundle stays off. Activation can't collide, and the bundle's autoloader never meets the newer copy.
• Saddle::adapter_is_current() also probes McpServer::get_tools(): if it wants arguments (0.7.0), the adapter is treated like WooCommerce's too-old 0.1.0 and the built-in transport serves /saddle/v1/mcp. The adapter's own default server keeps running for other plugins (Bridle's abilities included).
• Saddle_MCP::server_list() wraps every server-list call and skips a method that wants arguments, so a stray path can't fatal again.
• Changelog under the drafted 1.5.2.

Verified

• Live on the plug-press dev site (WP 7.1.2, Saddle + Pro + Analytics active): wp plugin activate mcp-adapter now succeeds (was the fatal); home, wp-json, /saddle/v1/mcp and the adapter's default server all answer; adapter_available=false, standalone_installed=true. A real session on /saddle/v1/mcp lists 94 tools (16 Bridle / Bridle KB); mcp-adapter-execute-ability runs bridle/list-conversations on the adapter's server.
• New tests: the probe (0.6.1-shaped vs 0.7.0-shaped server), server_list(), the guard (temp plugins dir, mcp-adapter-0.7.0 folder). composer test: 1453 OK (1 skipped, as on main). phpcs: no new findings in includes/saddle.php.
• The test install of the adapter on the dev site was removed afterwards.

🤖 Generated with Claude Code

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