fix(ux): tolerate legacy template encoding

services/ai_surface_html_readback_service.py

@@ -416,8 +416,30 @@ def _route_sources_for_template(root: Path, template_name: str) -> list[str]:
 
 def _evaluate_site_template(root: Path, path: Path) -> dict[str, Any]:
     relpath = _relative_template_path(root, path)
-    html = path.read_text(encoding="utf-8")
     high_priority = _is_high_priority_template(relpath)
+    try:
+        html = path.read_text(encoding="utf-8")
+    except UnicodeDecodeError as exc:
+        return {
+            "template": relpath,
+            "family": _template_family(relpath),
+            "priority": "P1" if high_priority else "P2",
+            "status": "critical",
+            "route_sources": _route_sources_for_template(root, relpath),
+            "guardrails": {
+                "compact_marker_present": False,
+                "benchmark_marker_present": False,
+                "professional_marker_present": False,
+            },
+            "finding_count": 1,
+            "findings": [{
+                "type": "template_encoding_error",
+                "severity": "critical",
+                "encoding": "utf-8",
+                "error": str(exc)[:300],
+            }],
+            "next_machine_action": "build_sitewide_ui_ux_repair_package",
+        }
     compact_marker_present = "data-density-guardrail=" in html
     benchmark_marker_present = "data-benchmark-guardrail=" in html
     professional_marker_present = any(marker in html for marker in PROFESSIONAL_GUARDRAIL_MARKERS)
@@ -569,6 +591,15 @@ def build_sitewide_ui_ux_repair_package(
                         "Add first-viewport status, next action, compact density marker, and evidence-on-demand pattern."
                     ),
                 })
+            if finding.get("type") == "template_encoding_error":
+                actions.append({
+                    "action": "normalize_template_encoding_utf8",
+                    "target_template": surface.get("template"),
+                    "safe_apply_hint": (
+                        "Convert the template to UTF-8, preserve visible Traditional Chinese copy, "
+                        "then rerun sitewide UI/UX inventory."
+                    ),
+                })
         repair_items.append({
             "template": surface.get("template"),
             "family": surface.get("family"),

tests/test_ai_automation_smoke_service.py

@@ -394,6 +394,29 @@ def test_sitewide_ui_ux_repair_package_prioritizes_controlled_template_repairs()
         assert package["repair_items"][0]["controlled_actions"]
 
 
+def test_sitewide_ui_ux_agent_reports_non_utf8_templates(tmp_path):
+    from services.ai_surface_html_readback_service import (
+        build_sitewide_ui_ux_agent_inventory,
+        build_sitewide_ui_ux_repair_package,
+    )
+
+    template_dir = tmp_path / "templates"
+    template_dir.mkdir()
+    (template_dir / "legacy_dashboard.html").write_bytes(b"\xa3 legacy dashboard")
+
+    inventory = build_sitewide_ui_ux_agent_inventory(root=tmp_path)
+    issue = inventory["issue_surfaces"][0]
+    package = build_sitewide_ui_ux_repair_package(source_inventory=inventory)
+
+    assert inventory["status"] == "warning"
+    assert issue["status"] == "critical"
+    assert issue["findings"][0]["type"] == "template_encoding_error"
+    assert package["repair_items"][0]["controlled_actions"][0]["action"] == (
+        "normalize_template_encoding_utf8"
+    )
+    assert package["safety"]["writes_database"] is False
+
+
 def test_surface_html_readback_check_is_part_of_ai_smoke(monkeypatch):
     from services import ai_automation_smoke_service as smoke