Implement field rendering using GenerateRml()

Now actually rendering fields when editors open!

view.lua changes:
- OpenEditor() now calls field.GenerateRml() for each field
- Concatenates all field RML into editor HTML
- Sets mainContent.inner_rml to display fields
- Added BindFieldEvents() to wire up input change events
- Field changes call editor:OnFieldChange()

springboard.rcss additions:
- .editor-container, .editor-title styling
- .field-row flex layout (label + input side-by-side)
- .field-label min-width for alignment
- .field-input styling with focus state
- .field-button for Browse/Pick buttons
- .field-separator for visual breaks
- .field-group for horizontal field groups

All RmlUi field classes already have GenerateRml():
- StringField → text input
- NumericField → number input with min/max/step
- BooleanField → checkbox
- ChoiceField → dropdown select
- ColorField, AssetField, MaterialField → input + button

Editors should now show actual working fields!

Author: claude

scen_edit/view/rcss/springboard.rcss

@@ -120,3 +120,69 @@ body#springboard {
     color: #cccccc;
     overflow-y: auto;
 }
+
+/* Editor field styles */
+.editor-container {
+    padding: 10dp;
+}
+
+.editor-title {
+    font-size: 16dp;
+    color: #ffffff;
+    margin-bottom: 15dp;
+    padding-bottom: 5dp;
+    border-bottom: 1dp #555555;
+}
+
+.field-row {
+    display: flex;
+    flex-direction: row;
+    align-items: center;
+    margin-bottom: 10dp;
+    gap: 10dp;
+}
+
+.field-label {
+    min-width: 120dp;
+    color: #cccccc;
+    font-size: 13dp;
+}
+
+.field-input {
+    flex: 1;
+    background-color: #3a3a3a;
+    color: #ffffff;
+    border: 1dp #555555;
+    padding: 5dp;
+    font-size: 13dp;
+}
+
+.field-input:focus {
+    border-color: #3a7ebf;
+    background-color: #2a2a2a;
+}
+
+.field-button {
+    background-color: #3a7ebf;
+    color: #ffffff;
+    border: 1dp #2a5f8f;
+    padding: 5dp 10dp;
+    cursor: pointer;
+}
+
+.field-button:hover {
+    background-color: #4a8ecf;
+}
+
+.field-separator {
+    height: 1dp;
+    background-color: #555555;
+    margin: 15dp 0dp;
+}
+
+.field-group {
+    display: flex;
+    flex-direction: row;
+    gap: 5dp;
+    margin-bottom: 10dp;
+}

scen_edit/view/view.lua

@@ -421,12 +421,12 @@ end
 
 function View:OpenEditor(editorName)
     Log.Notice("Opening editor: " .. editorName)
-    
+
     -- Create editor instance if not exists
     if not SB.editors then
         SB.editors = {}
     end
-    
+
     if not SB.editors[editorName] then
         local editorCfg = SB.editorRegistry[editorName]
         if editorCfg and editorCfg.editor then
@@ -436,19 +436,58 @@ function View:OpenEditor(editorName)
             return
         end
     end
-    
+
     local editor = SB.editors[editorName]
+    local editorCfg = SB.editorRegistry[editorName]
     local mainContent = self.mainDocument:GetElementById("main-content")
     if mainContent and editor then
-        -- For now, just show a placeholder
-        -- TODO: Implement full editor rendering with fields
-        mainContent.inner_rml = "<h3>Editor: " .. editorName .. "</h3><p>Fields will be rendered here</p>"
+        -- Render all fields to RML
+        local html = '<div class="editor-container"><h3 class="editor-title">' .. (editorCfg and editorCfg.caption or editorName) .. '</h3>'
+
+        -- Generate RML for each field in order
+        for _, fieldName in ipairs(editor.fieldOrder) do
+            local field = editor.fields[fieldName]
+            if field and field.GenerateRml then
+                html = html .. field:GenerateRml()
+            elseif field then
+                -- Fallback for fields without GenerateRml (like separators)
+                html = html .. '<div class="field-separator"></div>'
+            end
+        end
+
+        html = html .. '</div>'
+        mainContent.inner_rml = html
+
+        -- Bind field events
+        self:BindFieldEvents(editor)
     end
-    
+
     -- Highlight pressed button
     self:UpdateEditorButtonStates(editorName)
 end
 
+function View:BindFieldEvents(editor)
+    if not self.mainDocument or not editor or not editor.fields then
+        return
+    end
+
+    -- Bind change events for each field
+    for fieldName, field in pairs(editor.fields) do
+        local inputElement = self.mainDocument:GetElementById("field-" .. fieldName)
+        if inputElement then
+            inputElement:AddEventListener("change", function(event)
+                local value = inputElement.value
+                -- Update field value
+                field.value = value
+                -- Notify editor
+                if editor.OnFieldChange then
+                    editor:OnFieldChange(fieldName, value)
+                end
+            end)
+        end
+    end
+end
+
 function View:UpdateEditorButtonStates(activeEditorName)
     -- Remove pressed state from all buttons
     for name, _ in pairs(SB.editorRegistry) do