feat(packui): M113 第一批 —— 内容库页的导入/导出区（界面 + DTO + i18n + 拖拽落点）

导入入口（拖拽 + 路径输入 + 目标实例）与导出（格式选择 + 预检）的**界面层**，
数据面镜像 M111/M112 的管线报告（presenter DTO），进度整块复用下载页的安装面板。

## 落了什么

- pages/content/packui*：入口 / 进度块 / 结果块 / 导出预检块（每文件 ≤400）
  - 拖拽区（hover 变主色描边）+ 路径输入框 + 目标实例 chips
  - 进度：一行「步骤 n/5 · 解包覆盖内容」+ **下载页那块安装面板**（不另画进度条）
  - 结果：三态（Success/Partial/Failed）+ 缺文件逐条（Warn/Tertiary）+ 冲突逐条
    （成因 + 本次处置 + 可展开三方 SHA-1）+ 致命块（Error/ErrorContainer）
  - 导出：mrpack / CF 二选一 + 包名/版本/路径 + 预检「将内联 N 个文件 · 无法导出 M 项」
    + 逐条无法导出项 + 已知损失 + 确认写盘
- presenter/src/dto/pack{,/format,/import,/conflict,/export}.rs：镜像 core 报告的 DTO
  （三态、五阶段、三分类、十一条原因，全部 from_slug 与 core 稳定码逐字对齐）
- i18n：81 条 Pack* 键（content_entries! 尾部追加；golden.rs 同序同文）
- app/update.rs：FileDropped / FileHovered / FilesHoveredLeft → 内容库页（本版唯一的选文件通道）
- M109 的四个文件各一处插入：mod 声明 + Pack(..) 变体 + pack 字段 + 正列插入点

## 边界（如实）

- 没有系统文件选择框：依赖树里无对话框依赖，加它要动根 Cargo.toml + 许可门禁 +
  Linux 后端选型（影响单文件产物）。入口是拖拽 + 路径输入，原因写在界面上。
- 冲突没有逐文件决策：core 的 ConflictPolicy 是整次导入一个全局档，ConflictFile 是事后账。
  本批给「逐文件看 + 整体翻档（以包为准重新导入）」，文案明写「两者都留（改名）暂不支持」。
  默认一律 KeepUser——绝不默认覆盖用户改过的文件。
- 本批按钮半通：拖拽/路径/格式/实例/展开都真生效；「点导入真的开跑」「预检/确认写盘」
  要等第二批的 AppCommand 与事件通道（M109 rebase 到新 main 后按新形状写一次）。

crates/app-iced/src/pages/content/packui/model/tests.rs

@@ -0,0 +1,296 @@
+//! 导入/导出区视图模型的守门（M113）：阶段映射、预检计数、三方哈希、容忍/致命分野。
+//!
+//! 这里**不测画法**（画法靠出图），测的是「决策」：哪些数字进了哪一行、哪些字段被截短、
+//! 哪一态该出现哪一块。所有断言都能在没有图形环境的情况下跑。
+
+use std::path::PathBuf;
+
+use unlucky_i18n::Lang;
+use unlucky_presenter::dto::{
+    ConflictChoiceView, ConflictFileView, ConflictReasonView, ExportClassView, ExportFileView,
+    ExportPreviewView, ImportErrorView, ImportProgressView, ImportReportView, ImportStageView,
+    ImportStatusView, InstallStage, MissingFileView, MissingReasonView, PackFormatView,
+};
+
+use super::progress::{panel_progress, panel_stage, stage_line};
+use super::report::report_of;
+use super::report::short_sha;
+use super::{Pack, PackPageState};
+
+fn catalog() -> unlucky_i18n::Catalog {
+    Lang::En.catalog()
+}
+
+#[test]
+fn stage_line_counts_the_five_steps_in_order() {
+    let expected = [
+        (ImportStageView::Probe, "1/5"),
+        (ImportStageView::Extract, "2/5"),
+        (ImportStageView::Fetch, "3/5"),
+        (ImportStageView::Commit, "4/5"),
+        (ImportStageView::Register, "5/5"),
+    ];
+    for (stage, position) in expected {
+        let line = stage_line(stage, catalog());
+        assert!(line.contains(position), "{stage:?} 的步号不对：{line}");
+    }
+    // 阶段名要真的是「那一档」，不能五个阶段都显示同一句
+    let lines: Vec<String> = ImportStageView::ALL
+        .iter()
+        .map(|stage| stage_line(*stage, catalog()))
+        .collect();
+    for (index, line) in lines.iter().enumerate() {
+        for other in lines.iter().skip(index + 1) {
+            assert_ne!(line, other, "两个阶段的说明撞了：{line}");
+        }
+    }
+}
+
+#[test]
+fn no_progress_stage_maps_to_a_terminal_install_stage() {
+    // 进度面板只该画「在跑」的形态：映射到 Done/Failed/Cancelled 会让面板提前画成收尾/失败
+    for stage in ImportStageView::ALL {
+        let mapped = panel_stage(stage);
+        assert!(
+            !mapped.is_terminal(),
+            "{stage:?} 落到了终态 {mapped:?}（面板会画成收尾）"
+        );
+    }
+}
+
+#[test]
+fn panel_progress_carries_the_counts_and_the_pack_name() {
+    let progress = ImportProgressView {
+        stage: ImportStageView::Fetch,
+        done: 41,
+        total: 90,
+        current: Some("mods/sodium.jar".to_string()),
+        pack: "Better MC".to_string(),
+    };
+    let panel = panel_progress(&progress);
+    assert_eq!(panel.files_done, 41);
+    assert_eq!(panel.files_total, 90);
+    assert_eq!(panel.stage, InstallStage::Downloading);
+    // 面板第一行显示的就是包名（导入的对象是包，不是某个版本 id）
+    assert_eq!(panel.version, "Better MC");
+}
+
+#[test]
+fn unknown_counts_keep_the_bar_unknown() {
+    // total == 0 时不允许画确定态进度条（那是「静止的假进度」的来源）
+    let progress = ImportProgressView {
+        stage: ImportStageView::Probe,
+        done: 0,
+        total: 0,
+        current: None,
+        pack: "Pack".to_string(),
+    };
+    let panel = panel_progress(&progress);
+    assert_eq!(panel.files_total, 0);
+    assert_eq!(panel.speed_bps, 0, "导入没有字节速率，不许编");
+}
+
+#[test]
+fn sha_is_shortened_to_eight_chars() {
+    assert_eq!(
+        short_sha("9f2c41ab77de3350aa1b8c0d5e6f708192a3b4c5"),
+        "9f2c41ab"
+    );
+    assert_eq!(short_sha("abc"), "abc");
+    assert_eq!(short_sha(""), "");
+}
+
+fn preview(files: Vec<ExportFileView>) -> ExportPreviewView {
+    ExportPreviewView {
+        format: PackFormatView::Modrinth,
+        instance: "survival".to_string(),
+        name: "Survival".to_string(),
+        version: "1.0.0".to_string(),
+        target: PathBuf::from("C:/tmp/out.mrpack"),
+        files,
+        notes: Vec::new(),
+    }
+}
+
+fn export_file(
+    path: &str,
+    class: ExportClassView,
+    reason: unlucky_presenter::dto::ExportReasonView,
+) -> ExportFileView {
+    ExportFileView {
+        path: path.to_string(),
+        class,
+        reason,
+        bytes: 1000,
+        disabled: false,
+    }
+}
+
+#[test]
+fn preview_counts_match_the_three_classes() {
+    use unlucky_presenter::dto::ExportReasonView;
+    let view = preview(vec![
+        export_file(
+            "a.jar",
+            ExportClassView::Remote,
+            ExportReasonView::ModrinthSha1,
+        ),
+        export_file(
+            "b.jar",
+            ExportClassView::Inline,
+            ExportReasonView::NoRemoteMatch,
+        ),
+        export_file(
+            "c.jar",
+            ExportClassView::Inline,
+            ExportReasonView::MissingSha512,
+        ),
+        export_file(
+            "d.jar",
+            ExportClassView::Skipped,
+            ExportReasonView::SymbolicLink,
+        ),
+    ]);
+    assert_eq!(view.remote_count(), 1);
+    assert_eq!(view.inline_count(), 2);
+    assert_eq!(view.skipped_count(), 1);
+    assert_eq!(view.inline_bytes(), 2000);
+    assert!(!view.is_complete(), "有跳过项 ⇒ 包不完整");
+}
+
+#[test]
+fn the_head_line_carries_the_two_numbers_the_task_asks_for() {
+    use unlucky_presenter::dto::ExportReasonView;
+    let view = preview(vec![
+        export_file(
+            "b.jar",
+            ExportClassView::Inline,
+            ExportReasonView::NoRemoteMatch,
+        ),
+        export_file(
+            "c.jar",
+            ExportClassView::Inline,
+            ExportReasonView::MissingSha512,
+        ),
+        export_file(
+            "d.jar",
+            ExportClassView::Skipped,
+            ExportReasonView::UnsafePath,
+        ),
+    ]);
+    let block = super::export::preview_of(&view, catalog());
+    // 「将内联 N 个文件 · 无法导出 M 项」两个数字必须来自同一份 files，不许另算
+    assert!(
+        block.head.contains('2'),
+        "内联数没进 headline：{}",
+        block.head
+    );
+    assert!(
+        block.head.contains('1'),
+        "跳过数没进 headline：{}",
+        block.head
+    );
+    assert_eq!(block.skipped.len(), 1);
+    assert!(!block.complete);
+}
+
+#[test]
+fn report_keeps_tolerable_and_fatal_apart() {
+    let report = ImportReportView {
+        status: ImportStatusView::Failed,
+        format: Some(PackFormatView::Curseforge),
+        pack_name: Some("Broken".to_string()),
+        pack_version: None,
+        game_version: None,
+        loader: None,
+        version_id: None,
+        target: PathBuf::from("C:/tmp"),
+        files: Vec::new(),
+        conflicts: Vec::new(),
+        missing: vec![MissingFileView {
+            path: Some("mods/a.jar".to_string()),
+            display: "mods/a.jar".to_string(),
+            reason: MissingReasonView::Offline,
+            detail: String::new(),
+        }],
+        rejected: Vec::new(),
+        warnings: Vec::new(),
+        error: Some(ImportErrorView {
+            code: "pack_traversal".to_string(),
+            label: "路径穿越".to_string(),
+            message: "../etc/passwd".to_string(),
+            hint: Some("换一个来源".to_string()),
+        }),
+        registered: None,
+        bytes_written: 0,
+        rolled_back: true,
+    };
+    let block = report_of(&report, &PackPageState::default(), catalog());
+    assert!(block.fatal.is_some(), "致命块必须单独存在");
+    assert_eq!(block.missing.len(), 1, "容忍域仍要逐条列出");
+    assert!(!block.installed(), "Failed 不是「装上了」");
+    assert!(!block.can_overwrite, "没有冲突时不给翻档动作");
+}
+
+#[test]
+fn conflicts_default_to_keeping_the_user_copy() {
+    let report = ImportReportView {
+        status: ImportStatusView::Partial,
+        format: Some(PackFormatView::Modrinth),
+        pack_name: Some("Pack".to_string()),
+        pack_version: None,
+        game_version: None,
+        loader: None,
+        version_id: None,
+        target: PathBuf::from("C:/tmp"),
+        files: Vec::new(),
+        conflicts: vec![ConflictFileView {
+            path: "config/x.json".to_string(),
+            reason: ConflictReasonView::UserModified,
+            choice: ConflictChoiceView::KeepUser,
+            pack_sha1: "fixture".to_string(),
+            base_sha1: None,
+            disk_sha1: Some("disk".to_string()),
+            pack_size: 12,
+        }],
+        missing: Vec::new(),
+        rejected: Vec::new(),
+        warnings: Vec::new(),
+        error: None,
+        registered: None,
+        bytes_written: 0,
+        rolled_back: true,
+    };
+    let page = PackPageState::default();
+    let block = report_of(&report, &page, catalog());
+    assert_eq!(block.conflicts.len(), 1);
+    assert!(!block.conflicts[0].expanded, "默认收起");
+    assert_eq!(
+        block.conflicts[0].choice,
+        catalog().text(unlucky_i18n::Key::PackChoiceKeepUser),
+        "默认档必须是「保留我的」"
+    );
+    assert!(block.can_overwrite, "有冲突要能整体翻档");
+    assert!(block.overwrite_note.is_some(), "不支持「两者都留」要如实写");
+
+    // 展开的那一条才画三方哈希
+    let expanded = PackPageState {
+        expanded: Some("config/x.json".to_string()),
+        ..PackPageState::default()
+    };
+    let block = report_of(&report, &expanded, catalog());
+    assert!(block.conflicts[0].expanded);
+}
+
+#[test]
+fn an_idle_pack_has_nothing_to_draw_but_the_entry() {
+    let import = unlucky_presenter::dto::ImportState::default();
+    let export = unlucky_presenter::dto::ExportState::default();
+    let model = Pack::of(&import, &export, &PackPageState::default(), &[], catalog());
+    assert!(model.is_idle());
+    assert!(model.running.is_none());
+    assert!(model.report.is_none());
+    // 入口说明永远在（用户得知道可以拖什么、为什么没有「选择文件」按钮）
+    assert!(!model.drop_hint.is_empty());
+    assert!(!model.no_dialog_note.is_empty());
+}