fix(editor): constrain table structure hover size

* fix(editor): constrain table structure hover size

* fix(editor): improve DDL hover scrolling

* fix(editor): use CodeMirror tooltip lifecycle for hover layout

---------

Co-authored-by: zipg <4047349+zipg@users.noreply.github.com>
Co-authored-by: t8y2 <1156263951@qq.com>

apps/desktop/src/lib/__tests__/editor/sqlHoverLayout.spec.ts

@@ -0,0 +1,82 @@
+// @vitest-environment happy-dom
+
+import { describe, expect, it } from "vitest";
+import { constrainSqlHoverLayout, sqlHoverScrollbarMetrics } from "@/lib/editor/sqlHoverLayout";
+
+describe("constrainSqlHoverLayout", () => {
+  it("caps table structure hovers and scrolls oversized DDL inside the content area", () => {
+    const root = document.createElement("div");
+    const content = document.createElement("div");
+
+    constrainSqlHoverLayout(root, content);
+
+    expect(root.dataset.sqlStructureHover).toBe("true");
+    expect(root.style.width).toBe("80vw");
+    expect(root.style.maxWidth).toBe("900px");
+    expect(root.style.maxHeight).toBe("calc(50vh - 12px)");
+    expect(root.style.overflow).toBe("hidden");
+    expect(content.dataset.sqlStructureHoverContent).toBe("true");
+    expect(content.style.flex).toBe("0 1 auto");
+    expect(content.style.maxHeight).toBe("480px");
+    expect(content.style.maxWidth).toBe("100%");
+    expect(content.style.overflowX).toBe("hidden");
+    expect(content.style.overflowY).toBe("auto");
+    expect(content.style.overscrollBehavior).toBe("contain");
+    expect(content.style.scrollbarGutter).toBe("stable");
+    expect(root.querySelector('[data-sql-structure-hover-scrollbar="true"]')).not.toBeNull();
+    expect(root.querySelector('[data-sql-structure-hover-scrollbar-thumb="true"]')).not.toBeNull();
+  });
+
+  it("maps content scroll position to a proportional custom scrollbar thumb", () => {
+    expect(sqlHoverScrollbarMetrics(600, 1200, 300, 600)).toEqual({
+      maxScroll: 600,
+      maxThumbLeft: 300,
+      thumbLeft: 150,
+      thumbWidth: 300,
+    });
+
+    expect(sqlHoverScrollbarMetrics(600, 6000, 5400, 600)).toEqual({
+      maxScroll: 5400,
+      maxThumbLeft: 540,
+      thumbLeft: 540,
+      thumbWidth: 60,
+    });
+  });
+
+  it("keeps horizontal trackpad scrolling while the native scrollbar is hidden", () => {
+    const root = document.createElement("div");
+    const content = document.createElement("div");
+    Object.defineProperty(content, "clientWidth", { configurable: true, value: 600 });
+    Object.defineProperty(content, "scrollWidth", { configurable: true, value: 1200 });
+    constrainSqlHoverLayout(root, content);
+
+    const wheelEvent = new WheelEvent("wheel", { cancelable: true, deltaX: 120 });
+    content.dispatchEvent(wheelEvent);
+
+    expect(content.scrollLeft).toBe(120);
+    expect(wheelEvent.defaultPrevented).toBe(true);
+  });
+
+  it("starts the scrollbar on mount and stops responding after destroy", () => {
+    const root = document.createElement("div");
+    const content = document.createElement("div");
+    Object.defineProperty(content, "clientWidth", { configurable: true, value: 600 });
+    Object.defineProperty(content, "scrollWidth", { configurable: true, value: 2400 });
+    const controller = constrainSqlHoverLayout(root, content);
+    const track = root.querySelector<HTMLElement>('[data-sql-structure-hover-scrollbar="true"]')!;
+
+    // 挂载前未跑过 update，轨道仍隐藏
+    expect(track.hidden).toBe(true);
+    controller.mount();
+    expect(track.hidden).toBe(false);
+
+    const before = content.scrollLeft;
+    content.dispatchEvent(new WheelEvent("wheel", { cancelable: true, deltaX: 120 }));
+    expect(content.scrollLeft).toBe(before + 120);
+
+    controller.destroy();
+    const afterDestroy = content.scrollLeft;
+    content.dispatchEvent(new WheelEvent("wheel", { cancelable: true, deltaX: 120 }));
+    expect(content.scrollLeft).toBe(afterDestroy);
+  });
+});