fix(db): harden architecture_zone_bias axis-value validation (PR #174 review)

H1: guard that each axis value is a {token=weight} table before .items() —
a scalar (wall = 15000) or the array shape (wall = ["steel_frame"], a
plausible copy-paste from the sibling catalog's visual_bundle) now yields a
clean V-TT-06 error instead of a bare AttributeError. Mirrors the isinstance
guards already on zone_map and axes.
H2: exclude bool from the positive-integer weight check (weight = true is an
int subclass, previously slipped through as 1) — matches the guard
populate_color_register_bands already applies to its own values.
Two new ZoneBiasValidationTests cover both branches.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

tooling/economy-db/economy_import/traits.py

@@ -309,14 +309,23 @@ def populate_architecture_zone_bias(conn: sqlite3.Connection, dry_run: bool) ->
                         f"not one of {_TAG_AXES}"
                     )
                     continue
+                if not isinstance(weights, dict):
+                    errors.append(
+                        f"V-TT-06: architecture_zone_bias '{template_tag}.{zone_type_id}.{axis}': "
+                        f"each axis value must be a {{token = weight_bps}} table, got "
+                        f"{type(weights).__name__}"
+                    )
+                    continue
                 allowed = template_axis_tokens.get(template_tag, {}).get(axis, set())
-                for token, weight in (weights or {}).items():
+                for token, weight in weights.items():
                     if token not in allowed:
                         errors.append(
                             f"V-TT-06: architecture_zone_bias '{template_tag}.{zone_type_id}.{axis}': "
                             f"token '{token}' not in this template's visual_bundle.{axis} {sorted(allowed)}"
                         )
-                    if not isinstance(weight, int) or weight <= 0:
+                    # bool is an int subclass — exclude it explicitly, matching
+                    # populate_color_register_bands' guard on its own values.
+                    if isinstance(weight, bool) or not isinstance(weight, int) or weight <= 0:
                         errors.append(
                             f"architecture_zone_bias '{template_tag}.{zone_type_id}.{axis}.{token}': "
                             f"weight_bps must be a positive integer, got {weight!r}"

tooling/economy-db/test_traits.py

@@ -388,6 +388,29 @@ class ZoneBiasValidationTests(unittest.TestCase):
                 'wall = { brick_wall = 0 }\n'
             )
 
+    def test_non_dict_axis_value_reports_vtt06_not_a_traceback(self):
+        # A bare scalar or the array shape (a plausible copy-paste from the
+        # sibling catalog's `visual_bundle.wall = [...]`) must produce a clean
+        # V-TT-06 error, not an AttributeError crash on `.items()`.
+        import contextlib
+        import io
+
+        for bad in ("wall = 15000\n", 'wall = ["brick_wall"]\n'):
+            out = io.StringIO()
+            with contextlib.redirect_stdout(out):
+                with self.assertRaises(ImportAborted):
+                    self.populate(f"[bias.test_template.commercial_market]\n{bad}")
+            self.assertIn("V-TT-06", out.getvalue())
+            self.assertIn("must be a", out.getvalue())
+
+    def test_bool_weight_is_rejected(self):
+        # bool is an int subclass; `true` must not slip through as weight 1.
+        with self.assertRaises(ImportAborted):
+            self.populate(
+                '[bias.test_template.commercial_market]\n'
+                'wall = { brick_wall = true }\n'
+            )
+
     def test_missing_source_yields_zero_rows(self):
         traits.ARCHITECTURE_ZONE_BIAS_TOML = self.tmp / "missing.toml"
         self.assertEqual(traits.populate_architecture_zone_bias(self.conn, dry_run=True), 0)