Add pricing system with tiers, seasons, and calculator (v0.2.0)

- Create PricingTier enum for short/mid/long-term pricing
- Add Season class for seasonal pricing with date ranges
- Implement Calculator for price calculations with breakdown
- Add pricing meta box to Room post type
- Create Seasons admin page for managing seasonal pricing
- Add Pricing settings tab with tier thresholds
- Support weekend surcharges and configurable weekend days
- Add price column to room list admin

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

assets/css/admin.css

@@ -191,3 +191,135 @@
 	vertical-align: middle;
 	margin-right: 3px;
 }
+
+/* Price column */
+.column-price {
+	width: 120px;
+}
+
+.bnb-no-price {
+	color: #646970;
+	font-style: italic;
+}
+
+/* Pricing Meta Box */
+.bnb-pricing-table h4 {
+	margin: 0 0 10px 0;
+	padding: 0;
+	font-size: 13px;
+	font-weight: 600;
+	color: #1d2327;
+}
+
+.bnb-pricing-table tr:first-child th,
+.bnb-pricing-table tr:first-child td {
+	padding-top: 0;
+}
+
+.bnb-price-input-wrapper {
+	display: flex;
+	align-items: center;
+	gap: 8px;
+}
+
+.bnb-price-input-wrapper input {
+	width: 100px !important;
+}
+
+.bnb-price-unit {
+	color: #646970;
+	font-size: 13px;
+}
+
+/* Seasons Page */
+.bnb-seasons-description {
+	background: #fff;
+	border: 1px solid #c3c4c7;
+	border-left: 4px solid #72aee6;
+	padding: 12px 15px;
+	margin: 20px 0;
+}
+
+.bnb-seasons-description p {
+	margin: 5px 0;
+}
+
+.bnb-no-seasons {
+	background: #fff;
+	border: 1px solid #c3c4c7;
+	border-radius: 4px;
+	padding: 40px;
+	text-align: center;
+}
+
+.bnb-no-seasons p {
+	margin: 15px 0;
+}
+
+.bnb-no-seasons .button {
+	margin: 0 5px;
+}
+
+/* Season List Columns */
+.column-name {
+	width: 25%;
+}
+
+.column-dates {
+	width: 20%;
+}
+
+.column-modifier {
+	width: 20%;
+}
+
+.column-priority {
+	width: 10%;
+}
+
+.column-status {
+	width: 10%;
+}
+
+.bnb-modifier-visual {
+	font-size: 12px;
+	margin-left: 5px;
+}
+
+.bnb-status-active {
+	display: inline-flex;
+	align-items: center;
+	color: #00a32a;
+	font-weight: 600;
+}
+
+.bnb-status-active::before {
+	content: "\f147";
+	font-family: dashicons;
+	margin-right: 3px;
+}
+
+.bnb-status-inactive {
+	display: inline-flex;
+	align-items: center;
+	color: #646970;
+}
+
+.bnb-status-inactive::before {
+	content: "\f460";
+	font-family: dashicons;
+	margin-right: 3px;
+}
+
+/* Season Form */
+.bnb-season-form {
+	max-width: 800px;
+}
+
+.bnb-season-form .form-table th {
+	width: 180px;
+}
+
+.bnb-season-form input[type="text"].small-text {
+	width: 80px;
+}