feat: auto-generate all MQSC command methods from mapping-data.json

Eliminates hand-written methods by moving BEGIN marker to encompass all command methods. Updates mapping-data.json with generation metadata (pattern, name_required, name_default). 152 methods now fully generated.

Co-Authored-By: wphillipmoore-claude <255925739+wphillipmoore-claude@users.noreply.github.com>

Author: wphillipmoore