✨ feat(jtag): add Zynq JTAG presence detection via hw_server

- Add zynq_checker.py module to detect Zynq devices on JTAG chain
- Connects to hw_server via Vivado batch mode
- Parses JTAG device names to extract part number (e.g. XC7Z100)
- Integrates into Step 1 environment check in main_window.py
- Shows JTAG status in header (JTAG: XC7Z100 ✓)

src/gui/main_window.py

@@ -16,6 +16,7 @@ import customtkinter as ctk
 
 from config_manager import Config
 from vitis_checker import check_vitis, get_tool_status_dict
+from zynq_checker import check_zynq_jtag, get_zynq_status_dict
 from flash_programmer import full_flash_program, FlashResult
 from bitstream_programmer import full_bitstream_program, BitstreamResult
 from ip_verifier import ping_ip
@@ -75,6 +76,8 @@ class MainWindow(ctk.CTk):
         self._worker_thread: threading.Thread | None = None
         self._uart_available: bool = False
         self._uart_message: str = ""
+        self._zynq_jtag_present: bool = False
+        self._zynq_jtag_info = None
 
         self._load_config()
         self._build_ui()
@@ -185,6 +188,13 @@ class MainWindow(ctk.CTk):
         )
         self._ip_status.grid(row=0, column=2, sticky="e", padx=PADDING)
 
+        self._jtag_status = ctk.CTkLabel(
+            header,
+            text="JTAG: Checking...",
+            font=FONT_BODY,
+        )
+        self._jtag_status.grid(row=0, column=3, sticky="e", padx=PADDING)
+
     def _build_workflow_panel(self, parent: ctk.CTkFrame) -> None:
         """Build the step-by-step workflow panel."""
         panel = ctk.CTkFrame(parent, corner_radius=CORNER_RADIUS)
@@ -510,6 +520,22 @@ class MainWindow(ctk.CTk):
             self._ip_status.configure(text=f"IP: {ip} ✗", text_color=DANGER_COLOR)
             return False
 
+        # Check Zynq JTAG presence
+        self._log_message("  Checking Zynq JTAG presence...")
+        jtag_result = check_zynq_jtag(self._config, self._jtag_callback)
+        jtag_dict = get_zynq_status_dict(jtag_result)
+        if jtag_result.is_present:
+            self._zynq_jtag_present = True
+            self._zynq_jtag_info = jtag_result.devices[0]
+            part = jtag_result.devices[0].part_number
+            self._log_message(f"  ✓ Zynq {part} detected on JTAG chain")
+            self._jtag_status.configure(text=f"JTAG: {part} ✓", text_color=SUCCESS_COLOR)
+        else:
+            self._zynq_jtag_present = False
+            self._zynq_jtag_info = None
+            self._log_message(f"  ✗ Zynq not detected on JTAG: {jtag_result.error}")
+            self._jtag_status.configure(text="JTAG: Not detected", text_color=WARNING_COLOR)
+
         # Check UART availability
         self._log_message("  Checking UART serial port...")
         port = self._config.serial_port
@@ -568,6 +594,10 @@ class MainWindow(ctk.CTk):
         """Callback for flash programming progress."""
         self._log_message(f"  [{status}] {message}")
 
+    def _jtag_callback(self, status: str, message: str) -> None:
+        """Callback for JTAG scan progress."""
+        self._log_message(f"  [{status}] {message}")
+
     def _run_step_3_load_bootloader(self) -> bool:
         """Step 3: Load bootloader (BIT + ELF) and verify."""
         if not self._config: