Hosts page UX, draft/UI split, and managed hosts save summary

- Split effective-config session into Draft + Ui (IEffectiveConfigDraft, IEffectiveConfigUiState)
- Hosts: managed overlay, edit mode from table, validation deferred to blur/Escape/Enter
- Managed hosts save modal: line-level diff (add/remove/modify/order)
- Hosts group headers: editable/read-only badges, empty-group row, Effective names help
- hosts-ui.js for touch vs hover help; table inline bind oninput for live preview
- HostsEntryEditValidator and ManagedHostsPendingChangeDiff with tests

src/DnsmasqWebUI/Components/EffectiveConfig/Composition/EffectiveConfigSection.razor.css

@@ -262,6 +262,18 @@
     margin-bottom: 0;
 }
 
+/* Multivalue display mode: editable entry row (no list number; align with list content) */
+::deep .ec-field-value-list li.ec-multi-list-entry-point {
+    list-style: none;
+    margin-left: -1.25rem;
+    margin-top: 0.15rem;
+}
+
+::deep .ec-field-value-list li.ec-multi-list-empty-hint {
+    list-style: none;
+    margin-left: -1.25rem;
+}
+
 /* Long paths/URLs wrap; allow break anywhere so nothing is clipped */
 ::deep .ec-field-value-item {
     display: inline;