Extract important XAML properties into tree dump

TAP DLL: capture key properties from GetPropertyValuesChain during
bounds collection. Properties extracted:
- Text content: Text, Content, Header, PlaceholderText, Description,
  Title, Glyph (filtered: skip numeric handle references >10 digits)
- Accessibility: AutomationProperties.Name, AutomationProperties.AutomationId,
  AutomationProperties.HelpText
- State: IsEnabled, Visibility, IsChecked, IsSelected, IsOn, Orientation
- Other: Source, Tag

Properties are serialized as a JSON object in the TAP pipe output and
copied into Element.properties by graft_json_node. Text/Content/Header
values also populate Element.text for display.

The Win32 provider already populates properties (hwnd, style, visible,
enabled). XAML elements now get similar treatment, enabling AI consumers
to identify controls by their accessible names (e.g. 'Bold (Ctrl+B)').

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: asklar

src/providers/xaml_diag_common.cpp

@@ -172,6 +172,20 @@ static void graft_json_node(const json& j, Element& parent, const std::string& f
         }
     }
 
+    // Copy additional properties if present in TAP DLL output
+    if (j.contains("properties") && j["properties"].is_object()) {
+        for (auto& [key, val] : j["properties"].items()) {
+            if (val.is_string()) {
+                std::string v = sanitize(val.get<std::string>());
+                // Use Text/Content/Header as the element's display text if not already set
+                if (el.text.empty() && (key == "Text" || key == "Content" || key == "Header")) {
+                    el.text = v;
+                }
+                el.properties[key] = std::move(v);
+            }
+        }
+    }
+
     if (j.contains("children") && j["children"].is_array()) {
         for (auto& child : j["children"]) {
             // Pass bridge base (parentOffsetX/Y) — not accumulated — since

src/tap/lvt_tap.cpp

@@ -330,6 +330,44 @@ class LvtTap : public IObjectWithSite, public IVisualTreeServiceCallback2 {
                     foundOffset = true;
                 }
             }
+            // Extract important XAML properties for the tree dump.
+            // Only capture the first occurrence of each (most-specific in the chain).
+            // For text-like properties, check ValueType to avoid handle references
+            // (XAML serializes reference types as numeric handle IDs).
+            std::wstring valueType = props[i].ValueType ? props[i].ValueType : L"";
+            bool isTextProp = (name == L"Text" || name == L"Content" ||
+                               name == L"Header" || name == L"PlaceholderText" ||
+                               name == L"Description" || name == L"Title" ||
+                               name == L"Glyph");
+            // Heuristic: if value looks like a numeric handle (all digits, > 10 chars),
+            // it's a reference to a string object, not the string itself.
+            bool looksLikeHandle = value.size() > 10;
+            if (looksLikeHandle) {
+                bool allDigits = true;
+                for (wchar_t c : value) { if (c < L'0' || c > L'9') { allDigits = false; break; } }
+                looksLikeHandle = allDigits;
+            }
+            bool isStateProp = (name == L"AutomationProperties.Name" ||
+                                name == L"AutomationProperties.AutomationId" ||
+                                name == L"AutomationProperties.HelpText" ||
+                                name == L"IsEnabled" || name == L"Visibility" ||
+                                name == L"IsChecked" || name == L"IsSelected" ||
+                                name == L"IsOn" || name == L"Orientation" ||
+                                name == L"Source" || name == L"Tag");
+            bool isStringValue = valueType == L"String" || valueType == L"" ||
+                                 valueType == L"Boolean" || valueType == L"Int32" ||
+                                 valueType == L"Double" || valueType == L"Enum";
+            if (!value.empty() && value != L"0" && !looksLikeHandle &&
+                ((isTextProp && isStringValue) || isStateProp)) {
+                // Only store if not already present (first = most-specific)
+                bool found = false;
+                for (auto& p : node.properties) {
+                    if (p.first == name) { found = true; break; }
+                }
+                if (!found) {
+                    node.properties.emplace_back(name, value);
+                }
+            }
             if (props[i].Type) SysFreeString(props[i].Type);
             if (props[i].DeclaringType) SysFreeString(props[i].DeclaringType);
             if (props[i].ValueType) SysFreeString(props[i].ValueType);
@@ -490,6 +528,16 @@ class LvtTap : public IObjectWithSite, public IVisualTreeServiceCallback2 {
             }
         }
 
+        // Serialize extracted properties
+        if (!n.properties.empty()) {
+            j += L",\"properties\":{";
+            for (size_t i = 0; i < n.properties.size(); i++) {
+                if (i) j += L",";
+                j += L"\"" + Escape(n.properties[i].first) + L"\":\"" + Escape(n.properties[i].second) + L"\"";
+            }
+            j += L"}";
+        }
+
         if (!n.childHandles.empty()) {
             j += L",\"children\":[";
             for (size_t i = 0; i < n.childHandles.size(); i++) {