feat: 波长偏移修正 + 项目架构文档

- BandMathCalculator 支持 wavelength_offset 参数，公式波长统一加减偏移后匹配传感器波段
- WaterQualityIndexCalculator 全链传递偏移量 (band_math → calculate_one → calculate_many)
- WaterIndexCsvProcessor / Step7Handler / DataPreparationStep 传播偏移参数
- Step7/Step10 面板新增 QDoubleSpinBox 波长偏移控件 (±200nm, 默认0)
- 偏移控件去除单位后缀，避免编辑时需手动移动光标
- 新增 ARCHITECTURE.md 完整项目架构文档

src/gui/panels/step10_watercolor_panel.py

@@ -26,7 +26,7 @@ from PyQt5.QtWidgets import (
     QGroupBox, QLabel, QLineEdit, QComboBox, QCheckBox, QPushButton,
     QFileDialog, QMessageBox, QListWidget, QListWidgetItem,
     QAbstractItemView, QProgressBar, QTextEdit, QFrame,
-    QScrollArea, QSizePolicy,
+    QScrollArea, QSizePolicy, QDoubleSpinBox,
 )
 from PyQt5.QtGui import QFont
 from PyQt5.QtCore import Qt, QThread, pyqtSignal
@@ -72,6 +72,7 @@ class WaterIndexWorker(QThread):
         selected_formulas: List[str],
         waterindex_csv: str,
         work_dir: Optional[str] = None,
+        wavelength_offset: float = 0.0,
     ):
         super().__init__()
         self.sampling_csv_path = sampling_csv_path
@@ -79,6 +80,7 @@ class WaterIndexWorker(QThread):
         self.selected_formulas = selected_formulas
         self.waterindex_csv = waterindex_csv
         self.work_dir = work_dir
+        self.wavelength_offset = float(wavelength_offset)
 
     def run(self):
         try:
@@ -96,6 +98,7 @@ class WaterIndexWorker(QThread):
                 output_dir=self.output_dir,
                 selected_formulas=self.selected_formulas or None,
                 progress_callback=lambda m, p: self.progress.emit(m, p),
+                wavelength_offset=self.wavelength_offset,
             )
 
             self.progress.emit(
@@ -166,7 +169,23 @@ class Step10WatercolorPanel(QWidget):
         self.sampling_csv_file.label.setMinimumWidth(100)
         input_layout.addWidget(self.sampling_csv_file)
 
-        # 注意：彻底去掉了 self.meta_label 及其相关的布局代码
+        # ── 波长偏移修正 ──
+        offset_layout = QHBoxLayout()
+        offset_label = QLabel("波长偏移 (nm):")
+        offset_label.setMinimumWidth(120)
+        self.wavelength_offset_spin = QDoubleSpinBox()
+        self.wavelength_offset_spin.setRange(-200.0, 200.0)
+        self.wavelength_offset_spin.setValue(0.0)
+        self.wavelength_offset_spin.setDecimals(1)
+        self.wavelength_offset_spin.setSuffix("")
+        self.wavelength_offset_spin.setToolTip(
+            "传感器波长系统偏移修正量。正数=公式波长加偏移（如+100则w450→找≈w550的波段）；"
+            "负数=公式波长减偏移。默认0表示不做修正。"
+        )
+        offset_layout.addWidget(offset_label)
+        offset_layout.addWidget(self.wavelength_offset_spin)
+        offset_layout.addStretch()
+        input_layout.addLayout(offset_layout)
 
         input_group.setLayout(input_layout)
         layout.addWidget(input_group)
@@ -653,6 +672,7 @@ class Step10WatercolorPanel(QWidget):
             selected_formulas=selected,
             waterindex_csv=self._waterindex_csv,
             work_dir=work_dir,
+            wavelength_offset=self.wavelength_offset_spin.value(),
         )
         self._worker.progress.connect(self._on_progress)
         self._worker.finished_ok.connect(self._on_finished)

src/gui/panels/step7_inversion_panel.py

@@ -14,6 +14,7 @@ from PyQt5.QtWidgets import (
     QVBoxLayout, QHBoxLayout, QGroupBox, QFormLayout,
     QLabel, QPushButton, QMessageBox, QListWidget,
     QListWidgetItem, QSizePolicy, QWidget, QComboBox,
+    QDoubleSpinBox,
 )
 from PyQt5.QtCore import Qt
 from PyQt5.QtGui import QColor
@@ -238,6 +239,30 @@ class Step7InversionPanel(QWidget):
         params_group.setLayout(params_layout)
         main_layout.addWidget(params_group)
 
+        # ==========================================
+        # 波长偏移修正
+        # ==========================================
+        offset_group = QGroupBox("🔧 波长偏移修正")
+        offset_layout = QHBoxLayout()
+        offset_layout.setContentsMargins(20, 16, 20, 16)
+        offset_label = QLabel("统一偏移量 (nm):")
+        offset_label.setMinimumWidth(120)
+        self.wavelength_offset_spin = QDoubleSpinBox()
+        self.wavelength_offset_spin.setRange(-200.0, 200.0)
+        self.wavelength_offset_spin.setValue(0.0)
+        self.wavelength_offset_spin.setDecimals(1)
+        self.wavelength_offset_spin.setSuffix("")
+        self.wavelength_offset_spin.setToolTip(
+            "传感器波长系统偏移修正。公式中的目标波长统一加上此值后再匹配传感器波段。\n"
+            "例如：偏移 +100 意味着公式中的 w450 实际去找传感器 ~550nm 的波段。\n"
+            "默认 0 不做修正。适用于传感器标定漂移或不同传感器间的波段对齐。"
+        )
+        offset_layout.addWidget(offset_label)
+        offset_layout.addWidget(self.wavelength_offset_spin)
+        offset_layout.addStretch()
+        offset_group.setLayout(offset_layout)
+        main_layout.addWidget(offset_group)
+
         # ==========================================
         # 卡片 3：输出与执行
         # ==========================================
@@ -309,7 +334,8 @@ class Step7InversionPanel(QWidget):
             'training_csv_path': self.training_data_widget.get_path(),
             'formula_csv_file': self.formula_file.get_path(),
             'formula_names': selected_names,
-            'enabled': True
+            'enabled': True,
+            'wavelength_offset': self.wavelength_offset_spin.value(),
         }
         output_path = self.output_file.get_path()
         if output_path:
@@ -337,6 +363,12 @@ class Step7InversionPanel(QWidget):
         if 'output_path' in config:
             self.output_file.set_path(config['output_path'])
 
+        if 'wavelength_offset' in config:
+            try:
+                self.wavelength_offset_spin.setValue(float(config['wavelength_offset']))
+            except (ValueError, TypeError):
+                pass
+
     def _load_formulas_from_csv(self):
         """解析公式 CSV 文件并填充列表框"""
         csv_path = self.formula_file.get_path()