feat(explorer): extend diagnostic inspector to surface mp samples/counts

chore(explorer): add get_debug_trajectories_enabled helper

feat(explorer): instrument trajectories with debug diagnostics and un-silence helper exceptions

tests/test_diagnose_no_plot_trajectories.py

@@ -0,0 +1,49 @@
+import os
+import types
+
+import explorer
+
+
+def test_load_positions_empty_sets_diagnostics(monkeypatch):
+    # Monkeypatch load_positions to return empty positions
+    monkeypatch.setattr(
+        explorer, "load_positions", lambda db_path, window_size: ({}, {})
+    )
+    monkeypatch.setenv("EXPLORER_DEBUG_TRAJECTORIES", "1")
+
+    # Call build_trajectories_tab; it should set diagnostics and return without exception
+    explorer.build_trajectories_tab(db_path="unused", window_size="annual")
+
+    assert (
+        explorer._last_trajectories_diagnostics.get("stage") == "load_positions_empty"
+    )
+
+
+def test_select_helper_exception_is_captured(monkeypatch):
+    # Provide a minimal non-empty positions_by_window
+    positions = {"W1": {"mp1": (0.1, 0.2)}}
+
+    def fake_load_positions(db_path, window_size):
+        return positions, {}
+
+    monkeypatch.setattr(explorer, "load_positions", fake_load_positions)
+    # Ensure party_map maps the mp so centroids/path that invoke select_trajectory_plot_data
+    monkeypatch.setattr(explorer, "load_party_map", lambda db_path: {"mp1": "P1"})
+
+    # Patch select_trajectory_plot_data to raise
+    def bad_helper(*args, **kwargs):
+        raise ValueError("boom")
+
+    monkeypatch.setattr(explorer, "select_trajectory_plot_data", bad_helper)
+    monkeypatch.setenv("EXPLORER_DEBUG_TRAJECTORIES", "1")
+
+    explorer.build_trajectories_tab(db_path="unused", window_size="annual")
+
+    # Ensure the helper function has diagnostics attached and module diagnostics updated
+    assert getattr(explorer.select_trajectory_plot_data, "_last_diagnostics", None)
+    assert "exception" in explorer.select_trajectory_plot_data._last_diagnostics
+    assert (
+        explorer._last_trajectories_diagnostics.get("stage")
+        == "select_helper_exception"
+    )
+    assert "ValueError" in explorer._last_trajectories_diagnostics.get("exception", "")

tests/test_explorer_helpers_diagnostics.py

@@ -0,0 +1,22 @@
+import numpy as np
+from explorer_helpers import inspect_positions_for_issues
+
+
+def test_inspect_positions_for_issues_basic():
+    positions_by_window = {
+        "w1": {"mp1": (1.0, 2.0), "mp2": (float("nan"), float("nan"))},
+        "w2": {},
+    }
+    party_map = {"mp1": "P1"}
+    d = inspect_positions_for_issues(positions_by_window, party_map)
+
+    # basic keys still present
+    assert d["windows_count"] == 2
+    assert isinstance(d["mp_id_set"], set)
+    # new diagnostics
+    assert "mp_positions_count" in d
+    assert d["mp_positions_count"] >= 1
+    assert "mp_positions_sample" in d
+    assert isinstance(d["mp_positions_sample"], list)
+    assert "windows_with_no_positions" in d
+    assert isinstance(d["windows_with_no_positions"], list)