fix: tag_config for CTkTextbox + auto-save on file selection

- StatusDisplay: use tag_config (not tag_configure) for CTkTextbox
- FileSelector callbacks now trigger _auto_save_config() so that
  file path changes are persisted immediately to config.yaml
- This fixes the issue where UI file path changes weren't picked up
  by subsequent step executions

src/gui/main_window.py

@@ -247,6 +247,23 @@ class MainWindow(ctk.CTk):
                     setattr(self._config, attr, self._config._relative_path(abs_path))
         self._config.erase_all = self._erase_cb_var.get()
 
+    def _auto_save_config(self) -> None:
+        """Auto-save config to disk after UI changes.
+
+        Ensures that changes made in the UI (file paths, IP, etc.)
+        are persisted immediately so that _reload_config() picks them
+        up on the next step execution.
+        """
+        if not self._config:
+            return
+        self._sync_config_from_ui()
+        user_config_path = self._get_user_config_path()
+        self._config._config_path = user_config_path
+        try:
+            self._config.save()
+        except Exception:
+            pass  # Silently fail — user can manually save
+
     def _save_config(self) -> None:
         """Save current configuration to user config file (config.yaml).
 
@@ -293,6 +310,15 @@ class MainWindow(ctk.CTk):
         if self._config:
             self._config.zynq_ip = self._ip_string_var.get()
 
+    def _on_file_selected(self, path: str) -> None:
+        """Handle file selection — sync and auto-save to disk.
+
+        When the user selects a file via the browse dialog, immediately
+        sync the path to the Config object and persist it to YAML so
+        that subsequent step executions pick up the new value.
+        """
+        self._auto_save_config()
+
     # ── UI Construction ────────────────────────────────────────
 
     def _build_ui(self) -> None:
@@ -558,6 +584,7 @@ class MainWindow(ctk.CTk):
             panel,
             label_text="FSBL ELF (.elf):",
             file_types=[("ELF files", "*.elf"), ("All files", "*")],
+            callback=self._on_file_selected,
         )
         if self._config.fsbl_elf_path:
             resolved = self._config.resolve_path(self._config.fsbl_elf_path)
@@ -570,6 +597,7 @@ class MainWindow(ctk.CTk):
             panel,
             label_text="Bootloader BIT (.bit):",
             file_types=[("BIT files", "*.bit"), ("All files", "*")],
+            callback=self._on_file_selected,
         )
         if self._config.bootloader_bit_path:
             resolved = self._config.resolve_path(self._config.bootloader_bit_path)
@@ -582,6 +610,7 @@ class MainWindow(ctk.CTk):
             panel,
             label_text="Bootloader ELF (.elf):",
             file_types=[("ELF files", "*.elf"), ("All files", "*")],
+            callback=self._on_file_selected,
         )
         if self._config.bootloader_elf_path:
             resolved = self._config.resolve_path(self._config.bootloader_elf_path)
@@ -594,6 +623,7 @@ class MainWindow(ctk.CTk):
             panel,
             label_text="Bootloader BIN (.bin):",
             file_types=[("BIN files", "*.bin"), ("All files", "*")],
+            callback=self._on_file_selected,
         )
         if self._config.bootloader_bin_path:
             resolved = self._config.resolve_path(self._config.bootloader_bin_path)
@@ -628,6 +658,7 @@ class MainWindow(ctk.CTk):
             panel,
             label_text="Firmware BIN (.bin):",
             file_types=[("BIN files", "*.bin"), ("All files", "*")],
+            callback=self._on_file_selected,
         )
         if self._config.firmware_bin_path:
             resolved = self._config.resolve_path(self._config.firmware_bin_path)

src/gui/widgets.py

@@ -489,8 +489,8 @@ class StatusDisplay(ctk.CTkFrame):
         color = colors.get(status, INFO_COLOR)
 
         self._status_text.insert("1.0", message)
-        # Tag the entire text with the color
+        # Tag the entire text with the color (CTkTextbox uses tag_config)
-        self._status_text.tag_configure("status", foreground=color)
+        self._status_text.tag_config("status", foreground=color)
         self._status_text.tag_add("status", "1.0", "end")
 
         self._status_text.configure(state="disabled")