fix: bind copies to the visible product; state custody, purposes and clipboard exposure

CHANGELOG.md

@@ -5,6 +5,34 @@ All notable changes to Keyward are documented here. Format follows
 
 ## [Unreleased]
 
+### Added
+
+- **Per-entry purpose hints** (all three hosts): every known entry name now
+  carries a one-line consumer note — CI manifest signing, Racket-side
+  updater, macOS host `UpdateService`, update-manifest key id, Deep Check
+  pairing anchor, commercial-signing lifecycle. Unknown names get an
+  explicit "confirm what reads it before deleting" line, so the app itself
+  answers "can I delete this?" instead of silence. The delete confirmation
+  shows the same purpose line.
+- **Clipboard handling that tells the truth**: a copy reports that the raw
+  value is on the system clipboard where any app can read it, and auto-clears
+  after 30 s — only while the clipboard still holds Keyward's copy (change
+  count on macOS, a non-secret marker title on Windows, an ownership-marker
+  mime on Linux), so a later unrelated copy by the user is never erased.
+  Clipboard history/sync stays disclosed as out of Keyward's control.
+- **Plaintext custody stated in the app**: the intro, no-vault, snapshots
+  and About surfaces on all three hosts now say plainly that the vault file
+  and its snapshots are plain text on disk — not OS-encrypted custody — and
+  that the synced folder must be trusted.
+
+### Fixed
+
+- Rapidly selecting two products could leave rows and the copy target
+  bound to different sections: entry-list completions and copies are now
+  generation-guarded and bound to the product on screen; a stale copy is
+  skipped instead of landing a secret under a different header. A store
+  switch invalidates in-flight completions the same way.
+
 ### Fixed
 
 - Deep check now evaluates every private entry and all public anchors within its purpose. A valid update key no longer hides a corrupt or mismatched license key; multiple safe fingerprints remain labelled within the existing RPC row layout. Empty private entries are reported as unreadable. Regression coverage uses generated temporary keys only.

README.md

@@ -28,7 +28,9 @@ Rivet line — a Racket engine with native hosts — it keeps the vault file in
 your own synced folder and adds the discipline a plaintext store lacks:
 
 - **Never displayed, copy-only.** Key values are only ever returned by an
-  explicit copy-to-clipboard action.
+  explicit copy-to-clipboard action. The copy announces its own exposure
+  (any app can read the clipboard) and auto-clears after 30 s — unless
+  you have copied something else in between, which is never erased.
 - **Loss protection.** Every mutation snapshots the store first (append-only,
   inside the synced folder); writes are atomic and permissions are tightened.
 - **Deep check.** Parses each key (Ed25519 / RSA PKCS#8, base64-DER,

README.zh-CN.md

@@ -25,6 +25,8 @@ Keyward 是一个守护这些密钥的小型桌面应用。建在家族 Rivet 
 明文存储缺的那份纪律：
 
 - **永不显示，只进剪贴板。** 密钥值只通过显式的「复制到剪贴板」动作返回。
+  复制时会明示暴露面（任何应用都能读取剪贴板），并在 30 秒后自动清空——
+  期间你自己复制的其他内容永远不会被误删。
 - **防丢失。** 每次改动先对存储做快照（同步盘内、只追加）；写入原子化，
   权限收紧。
 - **深度校验。** 解析每把密钥（Ed25519 / RSA PKCS#8、base64-DER、

docs/GUIDE.zh-CN.md

@@ -188,7 +188,16 @@ raco rivet package     # 产物在 dist/keyward.app
 2. **鼠标悬停**在这一行上 → 行尾出现 **Copy** 按钮 → 点击；
    （或点行尾 `⋯` 菜单 → "Copy value to clipboard"）
 3. 值已进剪贴板，去粘贴。**界面上任何地方都不会显示值**——这是
-   故意的，防偷窥防误贴。
+   故意的，防偷窥防误贴；
+4. **30 秒后自动清空**。复制完成后状态栏会如实说明：原始值就在
+   系统剪贴板上，任何应用都能读到；30 秒后 Keyward 自动清空——
+   除非你期间又复制了别的东西，那份新内容永远不会被动。系统剪贴板
+   历史/同步不受 Keyward 控制，敏感值贴完即用、别久放。
+
+> 每个条目名下方都有一行**用途提示**（CI 签名 / Racket 更新器 /
+> macOS 宿主 / 清单代号 / 配对锚点……）。看到"没见过"的条目先读
+> 提示再决定动不动手——3/4/5 条个数的差异来自格式代际和新旧密钥
+> 组合，条条都有人消费，别凭感觉删。
 
 ### 4.2 新建一条
 

docs/USER-GUIDE.md

@@ -26,11 +26,11 @@ The vault is a plaintext INI file; file permissions and snapshots do not encrypt
 
 ## Network, keys and privacy
 
-The vault engine has no network operations. Clipboard copies and any user-chosen folder sync create additional exposure. Keyward is not an HSM, OS keychain or protection from an already compromised user session.
+The vault engine has no network operations. Copy-to-clipboard is the only path a value takes out of the app: the status line says so at each copy, notes that any application can read the clipboard, and auto-clears Keyward's copy after 30 s — a later unrelated copy of your own is never erased. What the app cannot control (OS clipboard history or cross-device clipboard sync) stays disclosed as out of scope. Any user-chosen folder sync creates additional exposure. Keyward is not an HSM, OS keychain or protection from an already compromised user session.
 
 ## Known limits
 
-Multi-key validation was corrected in #4. Backup/restore, orphan detection, clipboard exposure and packaged release evidence still require the work tracked in #3; do not infer a security certification.
+Multi-key validation was corrected in #4. In-app disclosure of plaintext custody, per-entry purpose hints, copy-consequence messaging, selection-bound copies and the 30 s clipboard auto-clear have landed in source (#3); packaged three-platform release evidence for that slice is still pending. Backup/restore and rotation workflow work remains tracked in #3; do not infer a security certification.
 
 ## Updates and removal
 

docs/USER-GUIDE.zh-CN.md

@@ -26,11 +26,11 @@ AGPL-3.0 许可的免费发布基础设施工具，不接商业激活。
 
 ## 联网、密钥与隐私
 
-密钥库引擎没有网络操作。剪贴板复制和用户选择的文件夹同步会增加暴露面。Keyward 不是 HSM 或系统钥匙串，也不能抵御已被攻陷的用户会话。
+密钥库引擎没有网络操作。值离开应用的唯一路径是复制到剪贴板：每次复制都会在状态栏明示这一点、注明任何应用都能读取剪贴板，并在 30 秒后自动清空 Keyward 的这次复制——期间你自己复制的其他内容永远不会被误删。应用无法控制的部分（系统剪贴板历史、跨设备剪贴板同步）如实声明为不在管辖范围。用户选择的文件夹同步会增加暴露面。Keyward 不是 HSM 或系统钥匙串，也不能抵御已被攻陷的用户会话。
 
 ## 已知限制
 
-多密钥校验已由 #4 修正。备份恢复、孤立条目检测、剪贴板暴露与打包发布证据仍需按 #3 推进；不构成安全认证。
+多密钥校验已由 #4 修正。明文托管的应用内说明、逐条目用途提示、复制后果明示、复制绑定所选产品与 30 秒剪贴板自动清空已进入源码（#3）；该切片的三平台打包发布证据仍待完成。备份恢复与轮换流程仍按 #3 推进；不构成安全认证。
 
 ## 更新与卸载