chore: more cleanup in the specs

specs/tabs.allium

@@ -8,6 +8,25 @@
 
 use "./layout.allium" as layout
 
+surface TabControlSurface {
+    facing _: TabOperator
+
+    provides:
+        OpenTabRequested(type, id, intent)
+        OpenTabInBackgroundRequested(type, id, intent)
+        CloseTabRequested(tab)
+        PinTabRequested(tab)
+        ClearTabsRequested()
+}
+
+surface TabRuntimeSurface {
+    facing _: TabRuntime
+
+    provides:
+        TabOpening(tab_type, intent)
+        ActiveTabChanged(active_tab)
+}
+
 -- ─── Tab types ────────────────────────────────────────────────
 
 -- 17 distinct tab types, each routing to a matching editor view.
@@ -29,6 +48,15 @@ value Tab {
     is_transient: Boolean         -- true = preview tab (italic title, replaceable)
 }
 
+surface TabSurface {
+    context tab: Tab
+
+    exposes:
+        tab.type
+        tab.id
+        tab.is_transient
+}
+
 -- ─── Tab categories ───────────────────────────────────────────
 
 -- 1. Singleton tool tabs: always one instance, never transient, id = type name.
@@ -161,6 +189,16 @@ value TabBarItem {
     is_dirty: Boolean                 -- dot indicator, only for post tabs
 }
 
+surface TabBarItemSurface {
+    context item: TabBarItem
+
+    exposes:
+        item.title
+        item.is_active
+        item.is_transient
+        item.is_dirty
+}
+
 -- Tab title resolution:
 --   post:            post.title from DB (listens post-updated events); no JS truncation
 --   media:           media.originalName; no JS truncation