feat(gui): M-1 / PR-Q.7 — dashboard CRT confidence column + alias-fold tooltip (C-5)

The CRT extractor (PR-Q.5/PR-Q.6) tags every target with a velocity_confidence
("CONFIRMED" / "LIKELY" / "AMBIGUOUS" / "UNKNOWN") and an optional alias_set
of candidate v_true folds. Until now the operator-facing targets table on the
Main View tab dropped that signal, so a single-PRI-only AMBIGUOUS reading
looked identical to a 3-PRI CONFIRMED one.

Changes:
  - Targets table column count 5 -> 6; new "Confidence" column between
    Velocity and Magnitude.
  - Module helper _confidence_display(label) -> (text, QColor):
      CONFIRMED  green  (DARK_SUCCESS)
      LIKELY     amber  (DARK_WARNING)
      AMBIGUOUS  red    (DARK_ERROR), prefixed with "? " so the row stands
                        out even when the operator's eyes skip the colour.
      UNKNOWN    gray   (DARK_TEXT) — legacy 32-bin / no CRT.
    Unrecognised future labels fall through to UNKNOWN.
  - Velocity cell carries a tooltip listing the CRT alias_set folds when
    present, so hovering reveals all plausible v_true candidates.
  - QColor pulled in from PyQt6.QtGui for the foreground tint.

Tests (TestDashboardConfidenceDisplay, +5):
  - CONFIRMED/LIKELY/AMBIGUOUS/UNKNOWN each map to expected text + colour.
  - AMBIGUOUS leads with "?" so it's visible without colour.
  - Unrecognised label "BANANA" falls back to UNKNOWN/gray.

Regression: 237/237 (test_v7 120 + test_GUI_V65_Tk 117). Ruff clean.

This closes audit M-1 / task PR-Q.7. The C-5 thread is end-to-end functional:
RTL emits 3 sub-frames (PR-Q.1) -> cosim agrees (PR-Q.2) -> v7 models carry
per-subframe params (PR-Q.4) -> processing.py runs CRT (PR-Q.5) -> workers
route through it (PR-Q.6) -> dashboard surfaces the confidence (PR-Q.7).

9_Firmware/9_3_GUI/v7/dashboard.py

@@ -41,6 +41,7 @@ from PyQt6.QtWidgets import (
     QPlainTextEdit, QStatusBar, QMessageBox,
 )
 from PyQt6.QtCore import Qt, QLocale, QTimer, pyqtSignal, pyqtSlot, QObject
+from PyQt6.QtGui import QColor
 
 from matplotlib.backends.backend_qtagg import FigureCanvasQTAgg
 from matplotlib.figure import Figure
@@ -87,6 +88,31 @@ def _make_dspin() -> QDoubleSpinBox:
     return sb
 
 
+# Confidence label colors for the targets table (PR-Q.7 / audit M-1).
+# CONFIRMED  green  — 3 sub-frames agreed via CRT
+# LIKELY     amber  — 2 of 3 sub-frames agreed
+# AMBIGUOUS  red    — only 1 sub-frame saw it; v_unamb-bounded reading
+# UNKNOWN    gray   — legacy 32-bin frame (no CRT was attempted)
+_CONFIDENCE_COLORS: dict[str, str] = {
+    "CONFIRMED": DARK_SUCCESS,
+    "LIKELY":    DARK_WARNING,
+    "AMBIGUOUS": DARK_ERROR,
+    "UNKNOWN":   DARK_TEXT,
+}
+
+
+def _confidence_display(confidence: str) -> tuple[str, QColor]:
+    """Map a RadarTarget.velocity_confidence string to (cell text, QColor).
+
+    AMBIGUOUS gets a leading "?" so it stands out in a long target list even
+    if the operator's eyes skip the color cue. Unknown confidence labels
+    (e.g. from a future model) fall back to "UNKNOWN" gray.
+    """
+    label = confidence if confidence in _CONFIDENCE_COLORS else "UNKNOWN"
+    text = f"? {label}" if label == "AMBIGUOUS" else label
+    return text, QColor(_CONFIDENCE_COLORS[label])
+
+
 # =============================================================================
 # Range-Doppler Canvas (matplotlib)
 # =============================================================================
@@ -486,9 +512,10 @@ class RadarDashboard(QMainWindow):
         tg_layout = QVBoxLayout(targets_group)
 
         self._targets_table_main = QTableWidget()
-        self._targets_table_main.setColumnCount(5)
+        self._targets_table_main.setColumnCount(6)
         self._targets_table_main.setHorizontalHeaderLabels([
-            "Range (m)", "Velocity (m/s)", "Magnitude", "SNR (dB)", "Track ID",
+            "Range (m)", "Velocity (m/s)", "Confidence",
+            "Magnitude", "SNR (dB)", "Track ID",
         ])
         self._targets_table_main.setAlternatingRowColors(True)
         self._targets_table_main.setSelectionBehavior(
@@ -1961,16 +1988,31 @@ class RadarDashboard(QMainWindow):
         for row, t in enumerate(targets):
             self._targets_table_main.setItem(
                 row, 0, QTableWidgetItem(f"{t.range:.0f}"))
-            self._targets_table_main.setItem(
-                row, 1, QTableWidgetItem(f"{t.velocity:.0f}"))
+
+            # PR-Q.7: velocity cell carries an alias-set tooltip so the operator
+            # can hover to see all CRT candidate folds; useful when confidence
+            # is LIKELY/AMBIGUOUS and the displayed velocity is just the best
+            # of several plausible v_true values.
+            vel_item = QTableWidgetItem(f"{t.velocity:.0f}")
+            if t.alias_set:
+                fold_strs = ", ".join(f"{v:+.1f}" for v in t.alias_set)
+                vel_item.setToolTip(f"CRT alias folds (m/s): {fold_strs}")
+            self._targets_table_main.setItem(row, 1, vel_item)
+
+            # PR-Q.7: confidence column. CONFIRMED = green, LIKELY = amber,
+            # AMBIGUOUS = red with leading "?", UNKNOWN = gray (legacy single-PRI).
+            conf_text, conf_color = _confidence_display(t.velocity_confidence)
+            conf_item = QTableWidgetItem(conf_text)
+            conf_item.setForeground(conf_color)
+            self._targets_table_main.setItem(row, 2, conf_item)
 
             mag_val = 10 ** (t.snr / 10) if t.snr > 0 else 0
             self._targets_table_main.setItem(
-                row, 2, QTableWidgetItem(f"{mag_val:.0f}"))
+                row, 3, QTableWidgetItem(f"{mag_val:.0f}"))
             self._targets_table_main.setItem(
-                row, 3, QTableWidgetItem(f"{t.snr:.1f}"))
+                row, 4, QTableWidgetItem(f"{t.snr:.1f}"))
             self._targets_table_main.setItem(
-                row, 4, QTableWidgetItem(str(t.track_id)))
+                row, 5, QTableWidgetItem(str(t.track_id)))
 
     def _update_diagnostics(self):
         # Connection indicators