feat: nation-op rename review — confirm/reject routes, client dialog, AGENTS.md (P4a, #16)

Wire the 'LLM proposes, player confirms' nation-rename flow end to end:
- server: POST /api/games/:id/nation-op/confirm|reject (404/400, version-bumped SSE state)
- client: confirmNationOp/rejectNationOp api helpers + NationOpDialog (editable rename) wired into the Action panel via a 'Nation proposals' trigger
- AGENTS.md: document the pendingNationOps mechanism, routes, nationRef resolution, stub-never-proposes

src/App.tsx

@@ -177,6 +177,10 @@ export default function App() {
   // gate the turn flow ("Jump forward" stays enabled while the advisor thinks) —
   // it only gates the advisor UI (the "Ask advisor" button + its hint).
   const [advisorBusy, setAdvisorBusy] = useState(false);
+  // Separate again: a pending nation-op confirm/reject is its own (fast,
+  // non-LLM) request. It gates only the nation-op dialog controls, never the
+  // turn flow — "Jump forward" stays usable while it is in flight.
+  const [opBusy, setOpBusy] = useState(false);
   // The id of the game the user is/was last in (mirrors localStorage) and the
   // list of saved games (newest first) shown on the home screen.
   const [activeGameId, setActiveGameId] = useState<string | null>(() => readActiveGameId());
@@ -401,6 +405,43 @@ export default function App() {
     [game, applyState],
   );
 
+  // Apply a pending nation op the model proposed (confirm, with an optional
+  // rename-name edit). Fast, non-LLM — gated by `opBusy`, not `busy`. The
+  // version-bumped state comes back in the response and the SSE `state` event.
+  const runConfirmNationOp = useCallback(
+    async (index: number, edits?: { name?: string }) => {
+      if (!game) return;
+      setOpBusy(true);
+      try {
+        const { game: g } = await api.confirmNationOp(game.id, index, edits);
+        applyState(g);
+        toast.success('Nation change applied');
+      } catch (e) {
+        toastError(e);
+      } finally {
+        setOpBusy(false);
+      }
+    },
+    [game, applyState],
+  );
+
+  // Drop a pending nation op (reject / dismiss). Fast, non-LLM — `opBusy`.
+  const runRejectNationOp = useCallback(
+    async (index: number) => {
+      if (!game) return;
+      setOpBusy(true);
+      try {
+        const { game: g } = await api.rejectNationOp(game.id, index);
+        applyState(g);
+      } catch (e) {
+        toastError(e);
+      } finally {
+        setOpBusy(false);
+      }
+    },
+    [game, applyState],
+  );
+
   // Jump forward: the single LLM call that commits the pending round. Only this
   // sets `busy` (the adds above are fast and non-LLM).
   const runJump = useCallback(async () => {
@@ -507,12 +548,15 @@ export default function App() {
           regions={regions}
           busy={busy}
           advisorBusy={advisorBusy}
+          opBusy={opBusy}
           advisors={advisors}
           onAddAction={runAddAction}
           onAddDiplomacy={runAddDiplomacy}
           onRemoveQueueItem={runRemoveQueueItem}
           onAdvisor={askAdvisor}
           onJump={runJump}
+          onConfirmNationOp={runConfirmNationOp}
+          onRejectNationOp={runRejectNationOp}
           onHome={goHome}
         />
       </>
@@ -551,12 +595,16 @@ interface GameScreenProps {
   busy: boolean;
   /** An advisor fetch is in flight — drives the advisor UI only (never the turn). */
   advisorBusy: boolean;
+  /** A nation-op confirm/reject is in flight — drives the dialog controls only. */
+  opBusy: boolean;
   advisors: string[];
   onAddAction: (a: string) => void;
   onAddDiplomacy: (to: string, m: string) => void;
   onRemoveQueueItem: (index: number) => void;
   onAdvisor: (p?: string) => void;
   onJump: () => void;
+  onConfirmNationOp: (index: number, edits?: { name?: string }) => void;
+  onRejectNationOp: (index: number) => void;
   onHome: () => void;
 }
 
@@ -579,12 +627,15 @@ function GameScreen({
   regions,
   busy,
   advisorBusy,
+  opBusy,
   advisors,
   onAddAction,
   onAddDiplomacy,
   onRemoveQueueItem,
   onAdvisor,
   onJump,
+  onConfirmNationOp,
+  onRejectNationOp,
   onHome,
 }: GameScreenProps) {
   // Which nation's dossier to show. Defaults to the player; remounts per game.
@@ -835,12 +886,15 @@ function GameScreen({
           game={game}
           busy={busy}
           advisorBusy={advisorBusy}
+          opBusy={opBusy}
           advisors={advisors}
           onAddAction={onAddAction}
           onAddDiplomacy={onAddDiplomacy}
           onRemoveQueueItem={onRemoveQueueItem}
           onAdvisor={onAdvisor}
           onJump={onJump}
+          onConfirmNationOp={onConfirmNationOp}
+          onRejectNationOp={onRejectNationOp}
           inWindow
         />
       </FloatingWindow>