feat(mcp,orchestrator,frontend): tool idea_restart_self, redemarrage autonome d'un agent — #288 (tool core self-only via requester MCP handshake, retour immediat {restartId, status: scheduled} puis orchestration detachee: snapshot reprise, stop PTY/structured, liberation Busy/mailbox, relance LaunchAgent meme conversation_id fresh_start=false, injection interne invisible; events domain/wire agentRestartRequested/PhaseChanged/Completed/Failed phases stopping/releasingInput/launching/resuming; CLI custom: separateurs exacts redemarrage de l'agent + etat termine/echoue, deduplication (restartId, event), verrouillage composer; TUI native: overlay AgentRestartOverlay sans injection xterm, progress/annonces projetes jusqu'a idle; QA verte: mcp_server restart_self 1/1, restart-self 3/3, backend self_restart_contract + events wire 2/2, frontend 3 suites 92/92, npm build, cargo check --workspace, fmt --check, diff --check; reserves hors perimetre: web-server 103/110 fixture PTY preexistante, 34 echecs npm test globaux listProjectSettings/web hors #288; scripts/ hors perimetre)

frontend/src/features/layout/LayoutGrid.cellControlsLayering.test.tsx

@@ -367,4 +367,26 @@ describe("LayoutGrid — ticket #48 cell control layering", () => {
       );
     },
   );
+
+  it("gives the native TUI restart overlay priority over other cell veils", async () => {
+    const setup = await makeSplitAgentGrid();
+    renderGrid(setup.gateways);
+    await flush();
+
+    act(() => {
+      setup.system.emit(busy(setup.agentId, true));
+      setup.system.emit({
+        type: "agentRestartRequested",
+        agentId: setup.agentId,
+        restartId: "restart-1",
+        reason: null,
+      });
+    });
+
+    const overlay = await screen.findByTestId("agent-restart-overlay");
+    expect(overlay.className).toContain("z-[4]");
+    expect(screen.queryByTestId("target-announcements-overlay")).toBeNull();
+    expect(screen.queryByText("------- redemarrage de l'agent -------")).toBeNull();
+    expect(controlsFor(setup.bId).controls.style.zIndex).toBe("5");
+  });
 });

frontend/src/features/layout/LayoutGrid.tsx

@@ -30,7 +30,9 @@ import { TerminalView, useWritePortal } from "@/features/terminals";
 import { useGateways } from "@/app/di";
 import { useProjectWorkState } from "@/features/workstate/useProjectWorkState";
 import {
+  AgentRestartOverlay,
   TargetAnnouncementsOverlay,
+  useAgentRestart,
   useTargetAnnouncements,
 } from "@/features/announcements";
 import { PluginLayoutCellView } from "@/features/plugins";
@@ -623,6 +625,7 @@ function LeafView({
   // write-portal veil can be mutually excluded with the F3 overlay (exactly one
   // full-cell veil at a time, F3 first). Same source the overlay itself reads.
   const { active: announcementBusyActive } = useTargetAnnouncements(agentId ?? "");
+  const { restart: agentRestart } = useAgentRestart(agentId ?? "");
   // Ticket #54 — local model-server launch state for this cell's pinned agent.
   // Correlated `agentId → profileId → opencode.localModelServerId → status` via
   // the shared hook (same reduction as `useAgents`). While the bound server is
@@ -1466,7 +1469,8 @@ function LeafView({
             is being injected into the agent's PTY, a grey veil with a centred
             message sits above the terminal. Only ever shown for an agent cell —
             and never together with the F3 overlay (exactly one veil, F3 first). */}
-        {!modelServerOverlay &&
+        {!agentRestart &&
+          !modelServerOverlay &&
           cellMode !== "custom" &&
           shouldShowWritePortalVeil(agentId != null, Boolean(overlay), busyActive) && (
           <div
@@ -1504,7 +1508,7 @@ function LeafView({
             an availability veil showing its live réflexions. Native TUI cells
             need the full-cell guard; custom CLI cells keep the canonical busy
             badge and composer lock only, matching their normal chat turn flow. */}
-        {!modelServerOverlay && cellMode !== "custom" && agentId != null && (
+        {!agentRestart && !modelServerOverlay && cellMode !== "custom" && agentId != null && (
           <TargetAnnouncementsOverlay
             projectId={projectId}
             agentId={agentId}
@@ -1517,7 +1521,7 @@ function LeafView({
             agent's bound local server is downloading its model / starting /
             probing, the empty terminal is covered rather than left to time out.
             Retracts at `ready`/`failed` (the predicate returns null then). */}
-        {modelServerOverlay && (
+        {!agentRestart && modelServerOverlay && (
           <div
             data-testid="model-server-overlay"
             role="status"
@@ -1634,6 +1638,9 @@ function LeafView({
             </div>
           </div>
         )}
+        {cellMode !== "custom" && agentId != null && agentRestart && (
+          <AgentRestartOverlay agentId={agentId} />
+        )}
       </div>
       {busyNotice && (
         <div