feat: add multi-terminal workbar and resizable sidebars

The assistant workbar now uses persistent application tabs with a permanent catalog entry point and supports multiple local or managed SSH terminals bound to the current project. Terminal sessions flow through the Main, preload, and renderer boundaries with bounded output, resize, lifecycle, and cleanup behavior.

The main sidebar and Magic Notes list now support pointer and keyboard resizing. Magic Notes can also hide and restore its list, remembers the chosen layout, and stacks its panes when the available width is narrow.

Closing a terminal tab ends its Shell session. Restored terminal tabs do not restart prior Shell processes and require an explicit reconnect.

Release note: 助手工作栏现可通过“+”打开多个本机或当前远程项目终端；主侧栏和魔法笔记列表支持拖拽调宽，魔法笔记列表可隐藏并记住布局。

src/main/ssh/ssh-connection-pool.test.ts

@@ -59,6 +59,8 @@ function createConnection(identity: SshPoolConnectionIdentity) {
   return {
     identity,
     isUsable: vi.fn(() => true),
+    onDisconnect: vi.fn(() => () => undefined),
+    openTerminalShell: vi.fn(),
     openAgentAttach: vi.fn(),
     runAgentDoctor: vi.fn(),
     runAgentBootstrapProbe: vi.fn(),
@@ -403,6 +405,13 @@ describe("authenticated ssh2 connection", () => {
           callback(undefined, channel);
         },
       ),
+      shell: vi.fn(
+        (
+          _window: unknown,
+          _options: unknown,
+          callback: (error: Error | undefined, stream: typeof channel) => void,
+        ) => callback(undefined, channel),
+      ),
       sftp: vi.fn(),
     });
     const target = createTarget();
@@ -425,6 +434,7 @@ describe("authenticated ssh2 connection", () => {
     );
 
     await connection.openAgentAttach(verifyAgentInstallationId("agent-v1"));
+    await connection.openTerminalShell({ cols: 132, rows: 43 });
     await expect(
       connection.probeRemotePackageBootstrap({
         operationId: "00000000-0000-4000-8000-000000000301",
@@ -470,6 +480,17 @@ describe("authenticated ssh2 connection", () => {
       },
       expect.any(Function),
     );
+    expect(client.shell).toHaveBeenCalledWith(
+      {
+        term: "xterm-256color",
+        cols: 132,
+        rows: 43,
+        width: 0,
+        height: 0,
+      },
+      { env: {}, x11: false },
+      expect.any(Function),
+    );
     expect(connection).not.toHaveProperty("exec");
   });
 
@@ -496,6 +517,7 @@ describe("authenticated ssh2 connection", () => {
       end: vi.fn(),
       destroy: vi.fn(),
       exec: vi.fn(),
+      shell: vi.fn(),
       sftp: vi.fn(),
     });
     const target = createTarget();
@@ -530,6 +552,7 @@ describe("authenticated ssh2 connection", () => {
       end: vi.fn(),
       destroy: vi.fn(),
       exec: vi.fn(),
+      shell: vi.fn(),
       sftp: vi.fn(),
     });
     const controller = new AbortController();
@@ -569,6 +592,7 @@ describe("authenticated ssh2 connection", () => {
           }, 0);
         },
       ),
+      shell: vi.fn(),
       sftp: vi.fn(),
     });
     const target = createTarget();
@@ -616,6 +640,7 @@ describe("authenticated ssh2 connection", () => {
           }, 0);
         },
       ),
+      shell: vi.fn(),
       sftp: vi.fn(),
     });
     const target = createTarget();
@@ -673,6 +698,7 @@ describe("authenticated ssh2 connection", () => {
           }, 0);
         },
       ),
+      shell: vi.fn(),
       sftp: vi.fn(),
     });
     const target = createTarget();
@@ -747,6 +773,7 @@ describe("authenticated ssh2 connection", () => {
           }, 0);
         },
       ),
+      shell: vi.fn(),
       sftp: vi.fn(),
     });
     const target = createTarget();