fix: RTL stepper connectors and duplicate clock icon in session wizard

SessionStepper copied MUI's LTR connector offsets (left: -50%), which in
the RTL admin drew each connector away from its previous step — a stray
line ran off the card edge past the last step and the first two steps
had no line between them. Swap the offsets so connectors extend toward
the previous step on the right, matching tauri's MUI-flipped rendering.

The acceptance-time field showed two clock icons (custom ClockP + the
browser's native picker indicator); hide the native one like the tauri
source, which has a single ClockField adornment.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

assets/admin/styles.css

@@ -952,3 +952,8 @@ html, body { max-width: 100%; overflow-x: hidden; }
 .dark .inv-table td { border-color: var(--border); }
 .inv-table tbody tr:hover { background: #f4f5fd; }
 .dark .inv-table tbody tr:hover { background: var(--surface-2); }
+
+/* input[type=time] با آیکون سفارشی (گام «ایجاد سرویس»): آیکون native مرورگر حذف
+   می‌شود تا ساعت دوتایی نشود — مثل مبدأ tauri که فقط یک ClockField دارد. */
+.time-input-plain::-webkit-calendar-picker-indicator { display: none; }
+.time-input-plain { appearance: none; -webkit-appearance: none; }