fix: ping_ip bool unpack, skip sub-step visibility, IP 192.168.100.11 after Step 3

- ping_ip returns bool, not tuple — fixed 2 unpack errors
- TftpSubStepFrame: _skipped set prevents set_phase from overwriting Skip
- set_expanded(True) before skip marking so UI shows it immediately
- After Step 3 success, fix IP to 192.168.100.11

src/gui/main_window.py

@@ -1419,8 +1419,11 @@ class MainWindow(ctk.CTk):
             all_results.append(True)  # 4b
             all_results.append(True)  # 4c
             if hasattr(self, '_tftp_sub_step_frame'):
+                self._tftp_sub_step_frame.set_expanded(True)
                 self._tftp_sub_step_frame.set_step_skipped("Download Verify")
                 self._tftp_sub_step_frame.set_step_skipped("CRC Check")
+                self._log_message("  ◌ Download Verify: Skip")
+                self._log_message("  ◌ CRC Check: Skip")
         else:
             # 4b: Download Verify
             self._log_message("Step 4b: TFTP download verify...")
@@ -1572,7 +1575,7 @@ class MainWindow(ctk.CTk):
 
             # Try ping configured IP first (fast, reliable)
             self._log_message(f"  Pinging {self._config.zynq_ip}...")
-            ok, _ = ping_ip(self._config.zynq_ip, timeout=2)
+            ok = ping_ip(self._config.zynq_ip, timeout=2)
             if ok:
                 discovered_ip = self._config.zynq_ip
                 self._log_message(f"  ✓ Zynq responds to ping at {discovered_ip}")
@@ -1587,7 +1590,7 @@ class MainWindow(ctk.CTk):
                     self._log_message(f"  ⏳ Waiting {boot_delay}s for late boot...")
                     time.sleep(boot_delay)
                     # Retry ping + scan after extra delay
-                    ok2, _ = ping_ip(self._config.zynq_ip, timeout=2)
+                    ok2 = ping_ip(self._config.zynq_ip, timeout=2)
                     if ok2:
                         discovered_ip = self._config.zynq_ip
                         self._log_message(f"  ✓ Zynq responds to ping at {discovered_ip}")
@@ -1805,6 +1808,13 @@ class MainWindow(ctk.CTk):
                 elapsed = time.time() - t_step_start
                 self._log_message(f"  ⏱ Step {i+1} completed in {elapsed:.0f}s")
 
+                # Step 3: After bootloader load, fix IP to 192.168.100.11
+                if i == 2 and success:
+                    self._config.zynq_ip = "192.168.100.11"
+                    if self._ip_string_var:
+                        self._ip_string_var.set("192.168.100.11")
+                    self._log_message("  IP set to 192.168.100.11")
+
                 # Step 2: mark sub-steps based on result
                 if i == 1 and hasattr(self, '_sub_step_frame'):
                     if success:

src/gui/widgets.py

@@ -871,6 +871,7 @@ class TftpSubStepFrame(ctk.CTkFrame):
 
         self._collapsed = True
         self._pulse_job: str | None = None
+        self._skipped: set[int] = set()
         self._substep_names = substep_names or ["Upload", "Download Verify", "CRC Check", "Reboot", "Boot Verify"]
         self._num_steps = len(self._substep_names)
 
@@ -936,6 +937,8 @@ class TftpSubStepFrame(ctk.CTkFrame):
 
         pct_text = f"{pct}%" if pct >= 0 else ""
         for i, item in enumerate(self._sub_items):
+            if i in self._skipped:
+                continue  # leave skipped items untouched
             if i < idx:
                 item["dot"].configure(text="●", text_color=_C_DONE)
                 item["label"].configure(text_color=_C_DONE)
@@ -980,6 +983,7 @@ class TftpSubStepFrame(ctk.CTkFrame):
         idx = self._substep_names.index(phase) if phase in self._substep_names else -1
         if idx < 0:
             return
+        self._skipped.add(idx)
         item = self._sub_items[idx]
         item["dot"].configure(text="◌", text_color=WARNING_COLOR)
         item["label"].configure(text_color=WARNING_COLOR)
@@ -1010,6 +1014,7 @@ class TftpSubStepFrame(ctk.CTkFrame):
 
     def reset(self) -> None:
         self._stop_pulse()
+        self._skipped.clear()
         _C = ACCENT_PENDING
         for i, item in enumerate(self._sub_items):
             item["dot"].configure(text="○", text_color=_C)