Automatically disable plugins when runtime errors or invalid plugin entry/metadata are detected. Adds a disable_plugin_after_failure helper to both Cloudlog_hooks and Plugin_manager that marks the plugin as 'disabled' in plugins_model and logs the reason. Cloudlog_hooks now disables plugins for missing hook methods, exceptions in filters/actions, invalid entry paths/class names, include failures, and construction failures. Plugin_manager disables plugins for invalid award method names, instantiation failures, missing award methods, award render exceptions, and include failures. Documentation updated to mention the new auto-disable behavior.
Introduce a plugin framework and management UI: adds Plugin Manager controller, Plugin_awards controller, Plugin_manager and Cloudlog_hooks libraries, Plugins_model, migration (268) to create the plugins table, and views for plugin manager and award pages. Integrates hooks into Logbook_model (qso.filter.before_save, qso.action.after_save, qso.action.after_edit), updates header to show award plugin entries and a Plugin Manager menu link, and bumps migration_version to 268. Also adds .gitignore rules, plugin index placeholder, docs and example plugin packages. The Plugin Manager supports uploading/installing ZIP packages, safe extraction, manifest validation, enable/disable/delete actions, and CSRF protection.
