feat(build): generate slot target objects

Add generated targets::<slot> wrapper objects so partial swaps read as target.put/append/replace while preserving existing lower-aware commands and IntoEffect wiring.

req: dx/006

req: codegen/001

req: codegen/002

req: component/003

examples/kanban.md

@@ -90,9 +90,9 @@ FormSurface {
 slhx reads this from hemplate Surface facts and generates scoped typed resources:
 
 ```rust
-use ui::board::{forms, slots};
+use ui::board::{forms, targets};
 
-ui::board::replace(slots::card, card.id, &CardView::from(card));
+targets::card.replace(card.id, &CardView::from(card));
 forms::create_card.clear("title");
 ui::render(&BoardView::from(board));
 ```
@@ -135,7 +135,7 @@ pub fn create_card(
     app.board.update(|board| board.insert_card(form.column, card.clone()));
 
     (
-        ui::board::append(slots::card, card.id, &CardView::from(card)),
+        targets::card.append(card.id, &CardView::from(card)),
         forms::create_card.clear("title"),
         // slhx-sync: queue atomic board state diff for sync
         SyncEffect::send_patch(atoms::board, Patch::insert_card(form.column, card)),
@@ -233,14 +233,14 @@ pub fn apply_board_patch(
             Effect::broadcast(
                 Channel::Board(app.board.id()),
                 Effect::batch(changed_cards.into_iter().map(|c|
-                    ui::board::replace(slots::card, c.id, &CardView::from(c))
+                    targets::card.replace(c.id, &CardView::from(c))
                 )),
             ),
         )),
 
         PatchResult::Conflict { canonical_board } => Effect::batch((
             Effect::set(atoms::BOARD, canonical_board.clone()),
-            ui::put(slots::board, &BoardView::from(canonical_board)),
+            targets::board.put(&BoardView::from(canonical_board)),
         )),
     }
 }
@@ -255,7 +255,7 @@ Server-authoritative on conflict. No Redux sagas. No React Query cache fades.
 ```rust
 #[slhx_sync::presence]
 pub fn user_joined(user: UserPresence) -> impl IntoEffect {
-    ui::board::append(slots::presence_user, user.id, &PresenceBadge::from(user))
+    targets::presence_user.append(user.id, &PresenceBadge::from(user))
 }
 ```