Implement Phase 7: Contact Form 7 Integration (v0.7.0)

Add custom CF7 form tags for booking requests:
- [bnb_building_select] - Building filter dropdown
- [bnb_room_select] - Room selection with capacity data
- [bnb_date_checkin/checkout] - Date pickers with validation
- [bnb_guests] - Guest count with capacity limits

Features:
- Server-side validation for all fields
- Real-time AJAX availability checking
- Automatic price calculation display
- Booking creation on form submission
- Guest record creation/linking
- Custom mail tags for CF7 templates

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

README.md

@@ -18,13 +18,14 @@ WP BnB Management enables WordPress to act as a full management system for B&B h
 - **Frontend Integration**: Gutenberg blocks, widgets, and shortcodes
 - **Auto-Updates**: Automatic update checks and installation from license server
 - **Development Mode**: License bypass for local development environments
-- **Contact Form 7 Integration**: Accept booking requests through forms (planned)
+- **Contact Form 7 Integration**: Accept booking requests and inquiries through CF7 forms
 
 ### Requirements
 
 - WordPress 6.0 or higher
 - PHP 8.3 or higher
 - Valid license key
+- Contact Form 7 (optional, for booking forms)
 
 ## Installation
 
@@ -143,6 +144,152 @@ Available sidebar widgets:
 - **Building Rooms** - List all rooms in a building
 - **Availability Calendar** - Mini calendar showing booking status
 
+## Contact Form 7 Integration
+
+The plugin integrates with Contact Form 7 to accept booking requests and inquiries. Custom form tags are provided for room selection, date pickers, and guest counts.
+
+### Custom Form Tags
+
+Use these tags in your CF7 forms:
+
+- `[bnb_building_select name]` - Building dropdown (optional filter for rooms)
+- `[bnb_room_select* name]` - Room dropdown with capacity data
+- `[bnb_date_checkin* name]` - Check-in date picker
+- `[bnb_date_checkout* name]` - Check-out date picker
+- `[bnb_guests* name]` - Guest count input
+
+### Tag Options
+
+**`[bnb_building_select]`**:
+
+- `first_as_label:"text"` - Placeholder text (default: "All Locations")
+
+**`[bnb_room_select]`**:
+
+- `building_field:"name"` - Link to building field for filtering
+- `first_as_label:"text"` - Placeholder text (default: "Select Room")
+
+**`[bnb_guests]`**:
+
+- `min:N` - Minimum guests (default: 1)
+- `max:N` - Maximum guests (default: 10)
+- `default:N` - Default value (default: 1)
+
+### Example Booking Form
+
+```txt
+<div class="wp-bnb-booking-form">
+<h3>Book Your Stay</h3>
+
+<div class="wp-bnb-form-row">
+[bnb_building_select building first_as_label:"All Locations"]
+</div>
+
+<div class="wp-bnb-form-row">
+[bnb_room_select* room building_field:"building" first_as_label:"Select a Room"]
+</div>
+
+<div class="wp-bnb-form-row-2col">
+<div class="wp-bnb-form-field">
+<label>Check-in</label>
+[bnb_date_checkin* check_in]
+</div>
+<div class="wp-bnb-form-field">
+<label>Check-out</label>
+[bnb_date_checkout* check_out]
+</div>
+</div>
+
+<div class="wp-bnb-availability-status"></div>
+
+<div class="wp-bnb-form-row">
+<label>Number of Guests</label>
+[bnb_guests* guests min:1 max:10 default:2]
+</div>
+
+<div class="wp-bnb-price-display"></div>
+
+<h4>Your Information</h4>
+
+<div class="wp-bnb-form-row-2col">
+<div class="wp-bnb-form-field">
+<label>First Name</label>
+[text* first_name]
+</div>
+<div class="wp-bnb-form-field">
+<label>Last Name</label>
+[text* last_name]
+</div>
+</div>
+
+<div class="wp-bnb-form-row">
+<label>Email</label>
+[email* your_email]
+</div>
+
+<div class="wp-bnb-form-row">
+<label>Phone</label>
+[tel your_phone]
+</div>
+
+<div class="wp-bnb-form-row">
+<label>Message</label>
+[textarea your_message]
+</div>
+
+[submit "Request Booking"]
+</div>
+```
+
+### Example Inquiry Form
+
+For room-specific inquiries, add the `wp-bnb-inquiry-form` class:
+
+```txt
+<div class="wp-bnb-inquiry-form">
+<h3>Inquire About This Room</h3>
+
+[hidden room default:123]
+
+<div class="wp-bnb-form-row">
+<label>Your Name</label>
+[text* your_name]
+</div>
+
+<div class="wp-bnb-form-row">
+<label>Email</label>
+[email* your_email]
+</div>
+
+<div class="wp-bnb-form-row">
+<label>Your Question</label>
+[textarea* your_message]
+</div>
+
+[submit "Send Inquiry"]
+</div>
+```
+
+### Form Features
+
+- **Availability Checking**: Real-time AJAX validation shows room availability
+- **Price Display**: Estimated total calculated and displayed automatically
+- **Room Filtering**: Rooms filter by building selection
+- **Date Validation**: Check-out must be after check-in, no past dates
+- **Capacity Validation**: Guest count validated against room capacity
+- **Automatic Booking**: Booking record created with "pending" status on submission
+- **Guest Linking**: Guest records created or linked by email address
+
+### Custom Mail Tags
+
+Use these in your CF7 mail templates:
+
+- `[_bnb_room_name]` - Room title
+- `[_bnb_building_name]` - Building name
+- `[_bnb_calculated_price]` - Formatted price
+- `[_bnb_nights]` - Number of nights
+- `[_bnb_booking_reference]` - Booking reference (after creation)
+
 ## Hooks and Filters
 
 Developers can customize behavior using these hooks: