Fix snapshots for plugins.

[dereuromark]

Resolves #463

Root Cause

The bug was in src/Util/TableFinder.php:72. The code incorrectly treated the --plugin option the same as --require-table, filtering tables to only include those with corresponding Table classes in the plugin. When creating
an initial migration snapshot for a plugin (before Table classes exist), this resulted in an empty migration.

The Fix

Changed line 72 in src/Util/TableFinder.php:

// Before (buggy)
if ($options['require-table'] === true || $options['plugin']) {

// After (fixed)  
if ($options['require-table'] === true) {

Behavior Changes

Before:

• --plugin option would filter tables to only include those with Table classes in the plugin
• Made it impossible to create initial snapshots for plugins with custom connections

After:

• --plugin option only determines where the migration file is saved
• All tables from the specified connection are included (excluding phinxlog tables)
• Use --require-table if you want to filter by existing Table classes

I wonder: Is including the plugins OK? or will this introduce too many tables or alike?