feat: prompt rules engine with store, priority, and product conditions (#32)

[DavidLambauer]

Summary

Fixes #32. Supersedes #54 (which was a Phase 3 bundle of #32 + #43; #43's config migration was dropped in favor of a separate coordinated effort with the translation module).

Adds an admin-managed rules engine for per-attribute AI prompts, with store scope, priority, and Magento catalog-rule conditions. Replaces the direct Config::getProductPrompt() lookup in Enricher with a priority-sorted rule resolver that falls back to the default prompt from the dynamic-row config.

What's new

Data layer:

• mageos_catalogai_prompt_rule table (10 columns, indexed on attribute_code + is_active)
• PromptRule model extending Magento\Rule\Model\AbstractModel with catalog rule conditions support
• Repository, collection, resource model

Service:

• PromptResolver::resolve(string $attributeCode, Product $product): ?string — filters active rules, sorts by priority DESC, returns the prompt from the first rule that matches store scope and product conditions. Falls back to Config::getProductPrompt() when no rules match.
• Enricher now delegates prompt lookup to PromptResolver

Admin UI:

• New "AI Prompt Rules" menu entry under Catalog
• Full CRUD: grid listing, edit form with collapsible fieldsets, mass-delete
• Form fields: name, active toggle, target attribute (dropdown of configured attributes), store views (multiselect), priority, prompt template
• Conditions fieldset using Magento's catalog rule conditions framework
• Preview/test AJAX endpoint — enter a SKU, see the resolved prompt with variables substituted

What's NOT in this PR

The #43 config migration to ai_integration_enrichment was designed before #46 landed and no longer matches the current config surface. It'll return as a separately-scoped PR coordinated with the translation module's shared "AI Services" section. None of the rules-engine code depends on it.

Test plan

• 149 unit tests, 314 assertions, green locally across PHP 8.2/8.3/8.4 (via CI)
• Run setup:upgrade — creates mageos_catalogai_prompt_rule table
• Navigate to Catalog → AI Prompt Rules — grid loads
• Create a rule: name, attribute, prompt, priority, save — persists on reload
• Two rules for the same attribute with different priorities — higher priority wins during enrichment
• Store-scoped rule only matches in its assigned store
• No rule matches — falls back to the default prompt from the dynamic-row config
• Preview endpoint — enter a SKU, see substituted prompt
• Mass-delete from the grid