Add Gravity Forms integration for quiz data hashing and category mapping

[Copilot]

Implements quiz response processing for the Action Pack Assessment form. Generates shareable hash codes from user responses and maps answers to WordPress categories via CSV configuration.

Implementation

Hash Generation

• CRC32 + base36 encoding produces 6-7 character URL-safe codes
• Consistent hashing (same inputs → same output)
• Replaces actionPack=tbd in confirmation URLs with generated hash

Data Extraction

• Extracts 5 optional fields: mode, size, offlineResiliency, pubSituation, disInfo
• Supports both custom input names and Gravity Forms field labels via pattern matching
• Null/unanswered values handled transparently

Category Mapping

• quizMap.csv maps answer values to category slugs
• Supports mode-specific mappings (before/during/after timeline)
• 24-hour transient cache to avoid repeated disk I/O
• Future use: content personalization and conditional recommendations

Gravity Forms Hooks

add_action('gform_pre_submission', ...);      // Extract data, generate hash, map categories
add_filter('gform_confirmation', ...);        // Inject hash into confirmation URL
add_action('gform_submission_started', ...);  // Preserve existing actionPack parameter

Example Hash

Input:  {mode: "before", size: "5", offlineResiliency: "2"}
Output: 1k3m9p2
URL:    https://emergencymode.news/action-pack/?actionPack=1k3m9p2

Files

• class-emfn-gravity-forms-handler.php - Main handler (singleton, 398 lines)
• quizMap.csv - Category mapping configuration (tall format: slug, answer, mode)
• GRAVITY-FORMS-README.md - Integration documentation
• Modified class-emfn-behavior-plugin.php to initialize handler when Gravity Forms active

Security

• Input sanitization via sanitize_text_field()
• Gravity Forms handles nonce verification before hooks fire
• actionPack is tracking-only, not authentication