fix(web): visual QA front-end items U4–U6, U13–U16 and copy list

- U4: form save failures toast the first problem and scroll/focus the first
  invalid field (policy draft, settings cards, resource drawers, subscription
  form) via lib/form-errors.
- U5: FormField keeps 8px between a hint and the next label.
- U6: file manager status bar keeps free space left-aligned, clear of the
  Agent button.
- U13: move/copy dialog stops "target is the source folder / inside the
  source" before requesting a preview (transferTargetProblem + tests).
- U14: account popover uses the solid float material.
- U15/U16: inbox tile hint shortened; TMDB assign dialog uses the shared
  Select and labelled fields (type, TMDB ID, note).
- Copy: "TMDB 已保存" spacing, API Key block no longer repeats the section
  title, whole-day intervals read "每 7 天", "最高级别:提示",
  "延后:已有计划在途", failed records show "未生成目标路径", upstream model
  column "默认模型".

Co-Authored-By: Claude Opus 5.5 <[email protected]>

apps/web/app/components/files/model.test.ts

@@ -23,6 +23,7 @@ import {
   shiftEpisodes,
   splitCommon,
   stemRange,
+  transferTargetProblem,
 } from "./model.ts";
 
 const order = ["a", "b", "c", "d", "e"];
@@ -257,3 +258,20 @@ describe("演示开关", () => {
     expect(resolveFilesMock({ dev: true, search: "?mock=0", storage })).toBe(false);
   });
 });
+
+describe("transferTargetProblem(U13)", () => {
+  const items = [
+    { root: "dl", path: "a/b.mkv" },
+    { root: "dl", path: "pack" },
+  ];
+  it("目标就是源所在目录 / 在源目录之内时拦下", () => {
+    expect(transferTargetProblem(items, { root: "dl", path: "a" })).toMatch(/已在这个目录里/);
+    expect(transferTargetProblem(items, { root: "dl", path: "pack/sub" })).toMatch(/目标在源目录之内/);
+    expect(transferTargetProblem([{ root: "dl", path: "x.mkv" }], { root: "dl", path: "" })).toMatch(/已在/);
+  });
+  it("其他目录、其他根放行", () => {
+    expect(transferTargetProblem(items, { root: "dl", path: "c" })).toBeNull();
+    expect(transferTargetProblem(items, { root: "lib", path: "a" })).toBeNull();
+    expect(transferTargetProblem(items, { root: "dl", path: "packs" })).toBeNull();
+  });
+});