diff --git a/README.md b/README.md
index 80c9da7..b1aac84 100644
--- a/README.md
+++ b/README.md
@@ -51,7 +51,7 @@ pnpm build:next
 
 安装器正式支持 **Linux x86_64（x64）**，脚本和运行时也支持在对应原生 runner 上发布 **aarch64（arm64）**；当前仓库内置 workflow 只生成 x64，arm64 需要在原生 ARM64 runner 上单独构建并发布。ARMv7/ARM32 仅实验性支持；Linux x86 32 位（`i386`、`i686`、`ia32`）明确不支持，因为 Node.js 24 和项目原生依赖没有可维护的官方构建。不要在 32 位系统上强行安装。
 
-发布包必须包含 `dist/`、生产依赖、匹配架构的 Node runtime、systemd 单元，以及 `SHA256SUMS`。签名文件 `SHA256SUMS.sig` 是可选增强校验，不需要为普通安装准备公钥。安装器默认直接安装最新版本：
+发布包必须包含 `dist/`、生产依赖、匹配架构的 Node runtime、systemd 单元、`uninstall.sh`，以及 `SHA256SUMS`。签名文件 `SHA256SUMS.sig` 是可选增强校验，不需要为普通安装准备公钥。安装器默认直接安装最新版本：
 
 ```bash
 curl --proto '=https' --tlsv1.2 -fsSL https://git.awaioi.com/awaioi/TallyNote/raw/branch/main/install.sh | sudo bash
@@ -72,6 +72,26 @@ curl --proto '=https' --tlsv1.2 -fsSL https://git.awaioi.com/awaioi/TallyNote/ra
 
 更新任务详情按发起管理员隔离；失败信息在浏览器中使用固定提示，不暴露服务器路径、命令输出或上游响应。系统同一时刻只允许一个更新任务。
 
+### 卸载
+
+安装完成后会提供 `/usr/local/sbin/tallynote-uninstall`。普通卸载会停止并禁用 TallyNote 的 systemd 单元，删除当前版本、更新辅助程序和已知配置，但保留 `/var/lib/tallynote` 以及更新备份，方便以后重新安装：
+
+```bash
+sudo /usr/local/sbin/tallynote-uninstall
+```
+
+如果确认不再需要数据库、附件、暂存、导出和更新备份，必须显式同时提供 `--purge-data --yes`：
+
+```bash
+sudo /usr/local/sbin/tallynote-uninstall --purge-data --yes --purge-config
+```
+
+卸载检测到未完成的更新状态时会停止并要求人工确认；确认更新已停止后再加 `--force`。也可以直接从公开仓库获取同一脚本执行普通卸载：
+
+```bash
+curl --proto '=https' --tlsv1.2 -fsSL https://git.awaioi.com/awaioi/TallyNote/raw/branch/main/uninstall.sh | sudo bash
+```
+
 公网反代必须使用 HTTPS，并在环境文件中设置真实的 `TALLYNOTE_PUBLIC_ORIGIN=https://...`、`TALLYNOTE_COOKIE_SECURE=true` 和明确的 `TALLYNOTE_TRUST_PROXY` 跳数（不要使用生产值 `true`）。
 
 ### 构建发布包
@@ -80,17 +100,17 @@ curl --proto '=https' --tlsv1.2 -fsSL https://git.awaioi.com/awaioi/TallyNote/ra
 
 ```bash
 pnpm install --frozen-lockfile
-pnpm release:build 1.1.1 ./release
+pnpm release:build 1.1.2 ./release
 ```
 
 将生成的 `tallynote-<版本>-linux-<架构>-<libc>.tar.gz` 上传到同一个 Gitea Release。推荐由 `.gitea/workflows/release.yml` 自动执行 `scripts/publish-gitea-release.sh`，统一生成并上传 `SHA256SUMS`；如果 CI 提供签名私钥，还会额外上传 `SHA256SUMS.sig`。CI 只需要 `GITEA_TOKEN`；签名私钥属于可选增强。
 
-版本由 `package.json` 和 Git tag 双重约束：两者必须相同（例如 `1.1.1` 与 `v1.1.1`），workflow 会在构建前拒绝不一致的 tag。发布一个版本：
+版本由 `package.json` 和 Git tag 双重约束：两者必须相同（例如 `1.1.2` 与 `v1.1.2`），workflow 会在构建前拒绝不一致的 tag。发布一个版本：
 
 ```bash
 git add .
-git commit -m "release: 1.1.1"
-git tag -a v1.1.1 -m "TallyNote 1.1.1"
+git commit -m "release: 1.1.2"
+git tag -a v1.1.2 -m "TallyNote 1.1.2"
 git push origin main --follow-tags
 ```
 
diff --git a/docs/release.md b/docs/release.md
index 12435ab..1e0bdc1 100644
--- a/docs/release.md
+++ b/docs/release.md
@@ -6,7 +6,7 @@ TallyNote 的发布包必须在目标 Linux 架构上构建。`better-sqlite3`
 
 ## 自动发布
 
-向 Gitea 推送符合 SemVer 的 tag（例如 `v1.1.1`）会触发 `.gitea/workflows/release.yml`：
+向 Gitea 推送符合 SemVer 的 tag（例如 `v1.1.2`）会触发 `.gitea/workflows/release.yml`：
 
 1. 在 Linux runner 上安装依赖，执行 `pnpm check`、`pnpm test` 和 `pnpm release:build`。
 2. 由 `scripts/publish-gitea-release.sh` 计算所有归档的 `SHA256SUMS`。
@@ -22,13 +22,13 @@ TallyNote 的发布包必须在目标 Linux 架构上构建。`better-sqlite3`
 ```bash
 pnpm install --frozen-lockfile
 pnpm check && pnpm test
-pnpm release:build 1.1.1 ./release
+pnpm release:build 1.1.2 ./release
 GITHUB_REPOSITORY=awaioi/TallyNote \
 GITEA_TOKEN=... \
-  ./scripts/publish-gitea-release.sh v1.1.1 ./release
+  ./scripts/publish-gitea-release.sh v1.1.2 ./release
 ```
 
-发布资产名称必须包含当前平台，例如 `tallynote-1.1.1-linux-x64-glibc.tar.gz`。同一个 Release 只保留一个 `SHA256SUMS`；有签名时再保留一个 `SHA256SUMS.sig`，签名覆盖清单完整原文。
+发布资产名称必须包含当前平台，例如 `tallynote-1.1.2-linux-x64-glibc.tar.gz`。同一个 Release 只保留一个 `SHA256SUMS`；有签名时再保留一个 `SHA256SUMS.sig`，签名覆盖清单完整原文。
 
 ## curl 安装
 
@@ -44,7 +44,7 @@ curl --proto '=https' --tlsv1.2 -fsSL https://git.awaioi.com/awaioi/TallyNote/ra
 
 已有安装默认拒绝安装不高于当前版本的 release；只有在明确执行 `--allow-downgrade`（或设置 `TALLYNOTE_ALLOW_DOWNGRADE=true`）时才允许回退版本。
 
-安装器拒绝预先存在的符号链接、非 root 拥有或对组/其他用户可写的安装、配置和备份目录。`--allow-unsigned` 作为旧版本兼容参数保留。
+安装器拒绝预先存在的符号链接、非 root 拥有或对组/其他用户可写的安装、配置和备份目录。发布包同时携带 `uninstall.sh`，安装后会落到 `/usr/local/sbin/tallynote-uninstall`。`--allow-unsigned` 作为旧版本兼容参数保留。
 
 安装布局：
 
@@ -58,6 +58,16 @@ curl --proto '=https' --tlsv1.2 -fsSL https://git.awaioi.com/awaioi/TallyNote/ra
 /etc/tallynote/tallynote.env
 ```
 
+## 卸载与数据保留
+
+默认卸载只移除发布代码、systemd 单元、更新辅助程序和已知配置，数据目录与更新备份不会删除：
+
+```bash
+sudo /usr/local/sbin/tallynote-uninstall
+```
+
+只有显式 `--purge-data --yes` 才会删除 SQLite、附件、暂存、导出、更新队列和备份；`--purge-config` 可在确认配置目录中没有其他文件后移除空配置目录。卸载器不会自动删除 `tallynote` 系统用户，也不会跟随符号链接删除目录。检测到 `.update-state` 或 `update-request.json` 时会拒绝执行，确认更新已经停止后使用 `--force`。
+
 ## 后台一键更新
 
 将环境文件中的 `TALLYNOTE_UPDATE_STRATEGY=systemd`、`TALLYNOTE_UPDATE_METADATA_URL` 和 `TALLYNOTE_UPDATE_ALLOWED_HOSTS` 配好后，后台“系统更新”会读取 Gitea 的 `/api/v1/repos/<owner>/<repo>/releases/latest`。检查结果只显示当前平台匹配且通过 SHA-256 校验的资产；如果配置了 `TALLYNOTE_UPDATE_PUBLIC_KEY_FILE` 并启用签名要求，再额外验证 Ed25519 签名。
diff --git a/install.sh b/install.sh
index 0575c66..eb8621f 100755
--- a/install.sh
+++ b/install.sh
@@ -373,7 +373,7 @@ normalize_release_tree() {
   fi
   find "$root" -type d -exec chmod 755 {} +
   find "$root" -type f -exec chmod 644 {} +
-  for item in "$root/bin"/* "$root/scripts"/*.sh "$root/runtime/bin"/*; do
+  for item in "$root/bin"/* "$root/scripts"/*.sh "$root/runtime/bin"/* "$root/uninstall.sh"; do
     [[ -f "$item" && ! -L "$item" ]] || continue
     chmod 755 "$item"
   done
@@ -541,10 +541,11 @@ rollback_install_if_needed() {
   fi
   if (( INSTALL_COMMITTED == 0 )) && [[ -n "$INSTALL_BACKUP_DIR" && -d "$INSTALL_BACKUP_DIR" ]]; then
     local backup_name target
-    for backup_name in tallynote.service tallynote-update.service tallynote-update.path tallynote.env update-signing-key.pub; do
+    for backup_name in tallynote.service tallynote-update.service tallynote-update.path tallynote-uninstall tallynote.env update-signing-key.pub; do
       case "$backup_name" in
         tallynote.env) target="$CONFIG_DIR/tallynote.env" ;;
         update-signing-key.pub) target="$CONFIG_DIR/update-signing-key.pub" ;;
+        tallynote-uninstall) target="/usr/local/sbin/tallynote-uninstall" ;;
         *) target="/etc/systemd/system/$backup_name" ;;
       esac
       [[ ! -L "$target" ]] || continue
@@ -586,6 +587,12 @@ backup_install_files() {
       cp -a -- "$target" "$directory/$name"
     fi
   done
+  target="/usr/local/sbin/tallynote-uninstall"
+  [[ ! -L "$target" ]] || die "现有卸载器不能是符号链接：$target"
+  if [[ -e "$target" ]]; then
+    [[ -f "$target" ]] || die "现有卸载器不是普通文件：$target"
+    cp -a -- "$target" "$directory/tallynote-uninstall"
+  fi
 }
 
 read_env_value() {
@@ -659,7 +666,7 @@ install_release() {
   [[ -x "$tmp/unpacked/bin/tallynote" ]] || die 'release archive must contain executable bin/tallynote'
   [[ -f "$tmp/unpacked/package.json" && -f "$tmp/unpacked/dist/server/index.js" && -f "$tmp/unpacked/dist/web/index.html" ]] || die 'release archive is incomplete'
   [[ -f "$tmp/unpacked/systemd/tallynote.service" && -f "$tmp/unpacked/systemd/tallynote-update.service" && -f "$tmp/unpacked/systemd/tallynote-update.path" ]] || die 'release archive is missing systemd units'
-  [[ -f "$tmp/unpacked/systemd/tallynote.env.example" && -x "$tmp/unpacked/scripts/tallynote-update.sh" && -x "$tmp/unpacked/scripts/tallynote-update-runner.sh" ]] || die 'release archive is missing update support files'
+  [[ -f "$tmp/unpacked/systemd/tallynote.env.example" && -x "$tmp/unpacked/scripts/tallynote-update.sh" && -x "$tmp/unpacked/scripts/tallynote-update-runner.sh" && -x "$tmp/unpacked/uninstall.sh" ]] || die 'release archive is missing update/uninstall support files'
   grep -Eq '"version"[[:space:]]*:[[:space:]]*"'"$version"'"([,}]|[[:space:]])' "$tmp/unpacked/package.json" || die 'release package version does not match requested version'
   ensure_root_directory "$PREFIX" 755
   ensure_root_directory "$PREFIX/releases" 755
@@ -817,7 +824,7 @@ main() {
   install_release "$archive" "$VERSION"
   release_dir="$PREFIX/releases/$VERSION"
   [[ -f "$release_dir/systemd/tallynote.service" && -f "$release_dir/systemd/tallynote-update.service" && -f "$release_dir/systemd/tallynote-update.path" ]] || die 'release package is missing systemd unit files'
-  [[ -f "$release_dir/systemd/tallynote.env.example" && -f "$release_dir/scripts/tallynote-update-runner.sh" ]] || die 'release package is missing update support files'
+  [[ -f "$release_dir/systemd/tallynote.env.example" && -f "$release_dir/scripts/tallynote-update-runner.sh" && -x "$release_dir/uninstall.sh" ]] || die 'release package is missing update/uninstall support files'
   install -d -m 755 /usr/local/libexec /etc/systemd/system
   local unit_tmp
   unit_tmp=$(mktemp -d)
@@ -830,6 +837,7 @@ main() {
   rm -rf "$unit_tmp"
   install -o root -g root -m 755 "$release_dir/scripts/tallynote-update.sh" /usr/local/sbin/tallynote-update
   install -o root -g root -m 755 "$release_dir/scripts/tallynote-update-runner.sh" /usr/local/libexec/tallynote-update-runner
+  install -o root -g root -m 755 "$release_dir/uninstall.sh" /usr/local/sbin/tallynote-uninstall
   ensure_root_directory "$(dirname -- "$DATA_DIR")/tallynote-backups" 700
   if [[ ! -f "$CONFIG_DIR/tallynote.env" ]]; then
     sed "s#/opt/tallynote#$PREFIX#g; s#/var/lib/tallynote#$DATA_DIR#g" "$release_dir/systemd/tallynote.env.example" > "$CONFIG_DIR/tallynote.env"
diff --git a/package.json b/package.json
index 56a3a40..f1a1723 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "tallynote",
-  "version": "1.1.1",
+  "version": "1.1.2",
   "private": true,
   "type": "module",
   "packageManager": "pnpm@9.0.6",
@@ -20,6 +20,7 @@
     "check": "tsc -p tsconfig.server.json --noEmit && tsc -p tsconfig.web-next.json --noEmit",
     "check:next": "tsc -p tsconfig.web-next.json --noEmit",
     "test": "vitest run",
+    "test:installer": "bash scripts/test-installer.sh && bash scripts/test-uninstaller.sh",
     "test:watch": "vitest",
     "test:e2e": "playwright test"
   },
diff --git a/scripts/build-release.sh b/scripts/build-release.sh
index cc81e30..583ea03 100755
--- a/scripts/build-release.sh
+++ b/scripts/build-release.sh
@@ -32,10 +32,11 @@ cp -a migrations/. "$stage/migrations/"
 cp package.json pnpm-lock.yaml "$stage/"
 cp -a bin/. "$stage/bin/"
 cp -a scripts/tallynote-update.sh scripts/tallynote-update-runner.sh "$stage/scripts/"
+cp uninstall.sh "$stage/uninstall.sh"
 cp -a systemd/tallynote.service systemd/tallynote-update.service systemd/tallynote-update.path systemd/tallynote.env.example "$stage/systemd/"
 node_path=$(command -v node)
 cp -L "$node_path" "$stage/runtime/bin/node"
-chmod 755 "$stage/bin/tallynote" "$stage/scripts"/*.sh "$stage/runtime/bin/node"
+chmod 755 "$stage/bin/tallynote" "$stage/scripts"/*.sh "$stage/runtime/bin/node" "$stage/uninstall.sh"
 
 # pnpm's default linker creates symlinks. A release archive is deliberately
 # symlink-free so the installer can reject traversal links deterministically.
diff --git a/scripts/test-installer.sh b/scripts/test-installer.sh
index b6f7a9a..eecad6b 100755
--- a/scripts/test-installer.sh
+++ b/scripts/test-installer.sh
@@ -82,10 +82,12 @@ bash -c '
 source_tmp="$tmp/source"
 mkdir -p "$source_tmp/dist/server" "$source_tmp/bin" "$source_tmp/scripts" "$source_tmp/runtime/bin"
 printf '%s\n' 'server' > "$source_tmp/dist/server/index.js"
+printf '%s\n' '#!/bin/sh' > "$source_tmp/uninstall.sh"
 printf '%s\n' '#!/bin/sh' > "$source_tmp/bin/tallynote"
 printf '%s\n' '#!/bin/sh' > "$source_tmp/scripts/runner.sh"
 printf '%s\n' 'node' > "$source_tmp/runtime/bin/node"
 chmod 755 "$source_tmp/bin/tallynote" "$source_tmp/scripts/runner.sh" "$source_tmp/runtime/bin/node"
+chmod 755 "$source_tmp/uninstall.sh"
 archive_tmp="$tmp/release.tar.gz"
 tar -C "$source_tmp" -czf "$archive_tmp" .
 bash -c '
@@ -99,6 +101,7 @@ bash -c '
   [[ "$(stat_mode "$destination/dist")" == 755 ]]
   [[ "$(stat_mode "$destination/dist/server/index.js")" == 644 ]]
   [[ "$(stat_mode "$destination/bin/tallynote")" == 755 ]]
+  [[ "$(stat_mode "$destination/uninstall.sh")" == 755 ]]
 ' _ "$installer_lib" "$archive_tmp" "$tmp/unpacked"
 
 # A normal public-release install only needs the detached SHA-256 manifest;
diff --git a/scripts/test-uninstaller.sh b/scripts/test-uninstaller.sh
new file mode 100755
index 0000000..de5e38a
--- /dev/null
+++ b/scripts/test-uninstaller.sh
@@ -0,0 +1,179 @@
+#!/usr/bin/env bash
+set -Eeuo pipefail
+
+root=$(cd -- "$(dirname -- "$0")/.." && pwd -P)
+bash -n "$root/uninstall.sh"
+
+tmp=$(cd "$(mktemp -d)" && pwd -P)
+cleanup() { rm -rf -- "$tmp" 2>/dev/null || true; }
+trap cleanup EXIT
+
+make_fixture() {
+  local fixture=$1
+  mkdir -p "$fixture/opt/tallynote/releases/1.1.1/dist" \
+    "$fixture/opt/tallynote/.update-work" \
+    "$fixture/var/lib/tallynote/files" \
+    "$fixture/var/lib/tallynote/staging" \
+    "$fixture/var/lib/tallynote/exports" \
+    "$fixture/var/lib/tallynote-backups" \
+    "$fixture/etc/tallynote" \
+    "$fixture/etc/systemd/system" \
+    "$fixture/usr/local/sbin" \
+    "$fixture/usr/local/libexec"
+  printf '%s\n' 'release' > "$fixture/opt/tallynote/releases/1.1.1/dist/index.js"
+  ln -s "$fixture/opt/tallynote/releases/1.1.1" "$fixture/opt/tallynote/current"
+  printf '%s\n' \
+    "TALLYNOTE_INSTALL_PREFIX=$fixture/opt/tallynote" \
+    "TALLYNOTE_DATA_DIR=$fixture/var/lib/tallynote" \
+    "TALLYNOTE_UPDATE_PUBLIC_KEY_FILE=$fixture/etc/tallynote/update-signing-key.pub" \
+    > "$fixture/etc/tallynote/tallynote.env"
+  chmod 600 "$fixture/etc/tallynote/tallynote.env"
+  printf '%s\n' 'fake public key' > "$fixture/etc/tallynote/update-signing-key.pub"
+  for unit in tallynote.service tallynote-update.service tallynote-update.path; do
+    printf '%s\n' "Description=TallyNote $unit" "WorkingDirectory=$fixture/opt/tallynote/current" "PathExists=$fixture/var/lib/tallynote/update-request.json" > "$fixture/etc/systemd/system/$unit"
+  done
+  printf '%s\n' '#!/usr/bin/env bash' 'PREFIX=${TALLYNOTE_INSTALL_PREFIX:-/opt/tallynote}' 'echo TallyNote' > "$fixture/usr/local/sbin/tallynote-update"
+  printf '%s\n' '#!/usr/bin/env bash' 'PREFIX=${TALLYNOTE_INSTALL_PREFIX:-/opt/tallynote}' 'echo TallyNote' > "$fixture/usr/local/libexec/tallynote-update-runner"
+  cp "$root/uninstall.sh" "$fixture/usr/local/sbin/tallynote-uninstall"
+  chmod 755 "$fixture/usr/local/sbin/tallynote-update" "$fixture/usr/local/libexec/tallynote-update-runner" "$fixture/usr/local/sbin/tallynote-uninstall"
+  printf '%s\n' 'sqlite' > "$fixture/var/lib/tallynote/tallynote.db"
+  printf '%s\n' 'backup' > "$fixture/var/lib/tallynote-backups/backup.db"
+}
+
+make_systemctl() {
+  local fixture=$1
+  cat > "$fixture/systemctl" <<'EOF'
+#!/usr/bin/env bash
+set -u
+printf '%s\n' "$*" >> "$TALLYNOTE_TEST_SYSTEMCTL_LOG"
+case "${1:-}" in
+  is-active) exit 0 ;;
+  stop|disable|daemon-reload) exit 0 ;;
+  *) exit 0 ;;
+esac
+EOF
+  chmod 755 "$fixture/systemctl"
+}
+
+run_uninstall() {
+  local fixture=$1
+  TALLYNOTE_UNINSTALL_TEST_MODE=true \
+  TALLYNOTE_UNINSTALL_ROOT="$fixture" \
+  TALLYNOTE_SYSTEMCTL_BIN="$fixture/systemctl" \
+  TALLYNOTE_TEST_SYSTEMCTL_LOG="$fixture/systemctl.log" \
+  bash "$root/uninstall.sh" "${@:2}"
+}
+
+fixture="$tmp/normal"
+make_fixture "$fixture"
+make_systemctl "$fixture"
+run_uninstall "$fixture"
+[[ -d "$fixture/var/lib/tallynote" && -f "$fixture/var/lib/tallynote/tallynote.db" ]]
+[[ -d "$fixture/var/lib/tallynote-backups" && -f "$fixture/var/lib/tallynote-backups/backup.db" ]]
+[[ ! -e "$fixture/opt/tallynote" || -z "$(find "$fixture/opt/tallynote" -mindepth 1 -print -quit 2>/dev/null)" ]]
+[[ ! -e "$fixture/etc/systemd/system/tallynote.service" ]]
+[[ ! -e "$fixture/usr/local/sbin/tallynote-update" ]]
+grep -n '^is-active.*tallynote-update.path' "$fixture/systemctl.log" >/dev/null
+grep -n '^stop tallynote-update.path' "$fixture/systemctl.log" >/dev/null
+path_stop=$(grep -n '^stop tallynote-update.path' "$fixture/systemctl.log" | head -n1 | cut -d: -f1)
+update_stop=$(grep -n '^stop tallynote-update.service' "$fixture/systemctl.log" | head -n1 | cut -d: -f1)
+main_stop=$(grep -n '^stop tallynote.service' "$fixture/systemctl.log" | head -n1 | cut -d: -f1)
+(( path_stop < update_stop && update_stop < main_stop ))
+
+# Re-running after the first uninstall is harmless and does not touch data.
+run_uninstall "$fixture"
+[[ -f "$fixture/var/lib/tallynote/tallynote.db" ]]
+
+# Purge requires the explicit acknowledgement flag and must fail before any
+# application files are removed.
+fixture="$tmp/purge"
+make_fixture "$fixture"
+make_systemctl "$fixture"
+if run_uninstall "$fixture" --purge-data >/dev/null 2>&1; then
+  echo 'expected --purge-data without --yes to fail' >&2
+  exit 1
+fi
+[[ -e "$fixture/opt/tallynote/current" && -f "$fixture/var/lib/tallynote/tallynote.db" ]]
+run_uninstall "$fixture" --purge-data --yes --purge-config
+[[ ! -e "$fixture/var/lib/tallynote" && ! -e "$fixture/var/lib/tallynote-backups" ]]
+[[ ! -e "$fixture/etc/tallynote" ]]
+
+# A custom data path must not overlap the release prefix; otherwise removing
+# releases could destroy data that the default uninstall promises to keep.
+fixture="$tmp/overlap"
+make_fixture "$fixture"
+make_systemctl "$fixture"
+printf '%s\n' \
+  "TALLYNOTE_INSTALL_PREFIX=$fixture/opt/tallynote" \
+  "TALLYNOTE_DATA_DIR=$fixture/opt/tallynote/releases/data" \
+  > "$fixture/etc/tallynote/tallynote.env"
+mkdir -p "$fixture/opt/tallynote/releases/data"
+printf '%s\n' protected > "$fixture/opt/tallynote/releases/data/keep.db"
+if run_uninstall "$fixture" >/dev/null 2>&1; then
+  echo 'expected overlapping data path to fail' >&2
+  exit 1
+fi
+[[ -f "$fixture/opt/tallynote/releases/data/keep.db" ]]
+
+# Trailing-slash aliases are rejected before the lexical overlap guard can be
+# bypassed.
+fixture="$tmp/trailing"
+make_fixture "$fixture"
+make_systemctl "$fixture"
+printf '%s\n' \
+  "TALLYNOTE_INSTALL_PREFIX=$fixture/opt/tallynote/" \
+  "TALLYNOTE_DATA_DIR=$fixture/var/lib/tallynote" \
+  > "$fixture/etc/tallynote/tallynote.env"
+if run_uninstall "$fixture" >/dev/null 2>&1; then
+  echo 'expected trailing slash path to fail' >&2
+  exit 1
+fi
+[[ -e "$fixture/opt/tallynote/current" && -f "$fixture/var/lib/tallynote/tallynote.db" ]]
+
+# Dot-component aliases are rejected as well; textual paths must be canonical
+# before the managed-directory containment checks run.
+fixture="$tmp/dot"
+make_fixture "$fixture"
+make_systemctl "$fixture"
+printf '%s\n' \
+  "TALLYNOTE_INSTALL_PREFIX=$fixture/opt/tallynote/." \
+  "TALLYNOTE_DATA_DIR=$fixture/var/lib/tallynote" \
+  > "$fixture/etc/tallynote/tallynote.env"
+if run_uninstall "$fixture" >/dev/null 2>&1; then
+  echo 'expected dot path component to fail' >&2
+  exit 1
+fi
+[[ -e "$fixture/opt/tallynote/current" && -f "$fixture/var/lib/tallynote/tallynote.db" ]]
+
+# Pending update state blocks destructive work until an operator overrides it.
+fixture="$tmp/pending"
+make_fixture "$fixture"
+make_systemctl "$fixture"
+printf '%s\n' pending > "$fixture/opt/tallynote/.update-state"
+if run_uninstall "$fixture" >/dev/null 2>&1; then
+  echo 'expected pending update state to block uninstall' >&2
+  exit 1
+fi
+[[ -e "$fixture/opt/tallynote/current" && -f "$fixture/var/lib/tallynote/tallynote.db" ]]
+
+# A current link escaping the release tree is rejected without deleting data.
+fixture="$tmp/link"
+make_fixture "$fixture"
+make_systemctl "$fixture"
+rm -f "$fixture/opt/tallynote/current"
+ln -s "$fixture/outside" "$fixture/opt/tallynote/current"
+if run_uninstall "$fixture" >/dev/null 2>&1; then
+  echo 'expected unsafe current symlink to fail' >&2
+  exit 1
+fi
+[[ -L "$fixture/opt/tallynote/current" && -f "$fixture/var/lib/tallynote/tallynote.db" ]]
+
+# dry-run must not call systemctl or remove files.
+fixture="$tmp/dry-run"
+make_fixture "$fixture"
+make_systemctl "$fixture"
+run_uninstall "$fixture" --dry-run >/dev/null
+[[ -e "$fixture/opt/tallynote/current" && -f "$fixture/var/lib/tallynote/tallynote.db" ]]
+[[ ! -e "$fixture/systemctl.log" ]]
+
+printf '%s\n' 'uninstaller shell tests passed'
diff --git a/tests/update-api.test.ts b/tests/update-api.test.ts
index 14be65e..5259f18 100644
--- a/tests/update-api.test.ts
+++ b/tests/update-api.test.ts
@@ -59,10 +59,10 @@ describe("更新 API", () => {
 
   function mockRelease() {
     const digest = "c".repeat(64);
-    const asset = `tallynote-1.1.2-${detectPlatform().target}-glibc.tar.gz`;
+    const asset = `tallynote-1.1.3-${detectPlatform().target}-glibc.tar.gz`;
     globalThis.fetch = (async (input: string | URL) => input.toString().endsWith("SHA256SUMS")
       ? new Response(`${digest}  ${asset}\n`, { status: 200 })
-      : new Response(JSON.stringify({ tag_name: "v1.1.2", assets: [{ name: "SHA256SUMS", browser_download_url: "https://updates.example/SHA256SUMS" }, { name: asset, browser_download_url: `https://updates.example/${asset}` }] }), { status: 200 })) as typeof fetch;
+      : new Response(JSON.stringify({ tag_name: "v1.1.3", assets: [{ name: "SHA256SUMS", browser_download_url: "https://updates.example/SHA256SUMS" }, { name: asset, browser_download_url: `https://updates.example/${asset}` }] }), { status: 200 })) as typeof fetch;
   }
 
   it("检查 release、创建受保护请求文件并拒绝重复任务", async () => {
@@ -70,21 +70,21 @@ describe("更新 API", () => {
     mockRelease();
     const checked = await app.inject({ method: "POST", url: "/api/update/check", headers: { origin: config.publicOrigin, cookie: session.cookies, "x-csrf-token": session.csrf }, payload: {} });
     expect(checked.statusCode).toBe(200);
-    expect(checked.json().latest).toMatchObject({ version: "1.1.2", compatible: true, integrityReady: true, isNewer: true });
+    expect(checked.json().latest).toMatchObject({ version: "1.1.3", compatible: true, integrityReady: true, isNewer: true });
     expect(checked.headers["cache-control"]).toBe("no-store");
     const tooSoon = await app.inject({ method: "POST", url: "/api/update/check", headers: { origin: config.publicOrigin, cookie: session.cookies, "x-csrf-token": session.csrf }, payload: {} });
     expect(tooSoon.statusCode).toBe(429);
     expect(tooSoon.headers["retry-after"]).toBeDefined();
 
-    const applied = await app.inject({ method: "POST", url: "/api/update/apply", headers: { origin: config.publicOrigin, cookie: session.cookies, "x-csrf-token": session.csrf }, payload: { version: "1.1.2", confirm: true } });
+    const applied = await app.inject({ method: "POST", url: "/api/update/apply", headers: { origin: config.publicOrigin, cookie: session.cookies, "x-csrf-token": session.csrf }, payload: { version: "1.1.3", confirm: true } });
     expect(applied.statusCode).toBe(202);
     const jobId = applied.json().job.id as string;
     const request = JSON.parse(readFileSync(config.updateRequestPath, "utf8")) as { jobId: string; expectedSha256: string; currentLink: string };
-    expect(request).toMatchObject({ jobId, version: "1.1.2", expectedSha256: "c".repeat(64), currentLink: config.currentLink });
+    expect(request).toMatchObject({ jobId, version: "1.1.3", expectedSha256: "c".repeat(64), currentLink: config.currentLink });
     expect(statSync(config.updateRequestPath).mode & 0o777).toBe(0o600);
 
     mockRelease();
-    const duplicate = await app.inject({ method: "POST", url: "/api/update/apply", headers: { origin: config.publicOrigin, cookie: session.cookies, "x-csrf-token": session.csrf }, payload: { version: "1.1.2", confirm: true } });
+    const duplicate = await app.inject({ method: "POST", url: "/api/update/apply", headers: { origin: config.publicOrigin, cookie: session.cookies, "x-csrf-token": session.csrf }, payload: { version: "1.1.3", confirm: true } });
     expect(duplicate.statusCode).toBe(409);
     expect(duplicate.json().error.code).toBe("UPDATE_IN_PROGRESS");
     const status = await app.inject({ method: "GET", url: "/api/update/status", headers: { cookie: session.cookies } });
@@ -95,7 +95,7 @@ describe("更新 API", () => {
 
   it("缺少确认或未启用 systemd 时不接受更新", async () => {
     const session = await login();
-    const invalid = await app.inject({ method: "POST", url: "/api/update/apply", headers: { origin: config.publicOrigin, cookie: session.cookies, "x-csrf-token": session.csrf }, payload: { version: "1.1.2" } });
+    const invalid = await app.inject({ method: "POST", url: "/api/update/apply", headers: { origin: config.publicOrigin, cookie: session.cookies, "x-csrf-token": session.csrf }, payload: { version: "1.1.3" } });
     expect(invalid.statusCode).toBe(400);
     process.env.TALLYNOTE_UPDATE_STRATEGY = "disabled";
     const disabledConfig = loadConfig();
@@ -108,7 +108,7 @@ describe("更新 API", () => {
     mockRelease();
     const checked = await app.inject({ method: "POST", url: "/api/update/check", headers: { origin: config.publicOrigin, cookie: owner.cookies, "x-csrf-token": owner.csrf }, payload: {} });
     expect(checked.statusCode).toBe(200);
-    const applied = await app.inject({ method: "POST", url: "/api/update/apply", headers: { origin: config.publicOrigin, cookie: owner.cookies, "x-csrf-token": owner.csrf }, payload: { version: "1.1.2", confirm: true } });
+    const applied = await app.inject({ method: "POST", url: "/api/update/apply", headers: { origin: config.publicOrigin, cookie: owner.cookies, "x-csrf-token": owner.csrf }, payload: { version: "1.1.3", confirm: true } });
     expect(applied.statusCode).toBe(202);
     const jobId = applied.json().job.id as string;
     database.sqlite.prepare("UPDATE update_jobs SET error_message=? WHERE id=?").run("/var/lib/tallynote/secret-command-output", jobId);
@@ -126,7 +126,7 @@ describe("更新 API", () => {
   it("应用前重新校验失败时写入失败审计", async () => {
     const session = await login("update-audit");
     globalThis.fetch = (async () => new Response("upstream unavailable", { status: 503 })) as typeof fetch;
-    const response = await app.inject({ method: "POST", url: "/api/update/apply", headers: { origin: config.publicOrigin, cookie: session.cookies, "x-csrf-token": session.csrf }, payload: { version: "1.1.2", confirm: true } });
+    const response = await app.inject({ method: "POST", url: "/api/update/apply", headers: { origin: config.publicOrigin, cookie: session.cookies, "x-csrf-token": session.csrf }, payload: { version: "1.1.3", confirm: true } });
     expect(response.statusCode).toBe(502);
     const audit = database.sqlite.prepare("SELECT outcome FROM audit_events WHERE action='update.apply_requested' ORDER BY id DESC LIMIT 1").get() as { outcome: string } | undefined;
     expect(audit?.outcome).toBe("failure");
diff --git a/tests/update.test.ts b/tests/update.test.ts
index e1ec2cd..2f887f6 100644
--- a/tests/update.test.ts
+++ b/tests/update.test.ts
@@ -273,17 +273,17 @@ describe("更新元数据缓存", () => {
     prepareDataDirectories(config);
     const database = openDatabase(config);
     const digest = "b".repeat(64);
-    const platformAsset = `tallynote-1.1.2-${detectPlatform().target}-glibc.tar.gz`;
+    const platformAsset = `tallynote-1.1.3-${detectPlatform().target}-glibc.tar.gz`;
     const sums = `${digest}  ${platformAsset}\n`;
     const signature = sign(null, Buffer.from(sums), privateKey);
     globalThis.fetch = (async (input: string | URL) => input.toString().endsWith("SHA256SUMS.sig")
       ? new Response(signature)
       : input.toString().endsWith("SHA256SUMS")
       ? new Response(sums)
-      : new Response(JSON.stringify({ tag_name: "v1.1.2", published_at: "2026-08-28T00:00:00Z", assets: [{ name: "SHA256SUMS", browser_download_url: "https://updates.example/SHA256SUMS" }, { name: "SHA256SUMS.sig", browser_download_url: "https://updates.example/SHA256SUMS.sig" }, { name: platformAsset, browser_download_url: `https://updates.example/${platformAsset}` }] }), { status: 200 })) as typeof fetch;
+      : new Response(JSON.stringify({ tag_name: "v1.1.3", published_at: "2026-08-28T00:00:00Z", assets: [{ name: "SHA256SUMS", browser_download_url: "https://updates.example/SHA256SUMS" }, { name: "SHA256SUMS.sig", browser_download_url: "https://updates.example/SHA256SUMS.sig" }, { name: platformAsset, browser_download_url: `https://updates.example/${platformAsset}` }] }), { status: 200 })) as typeof fetch;
     try {
       const result = await checkForUpdate(database.sqlite, config);
-      expect(result.latest).toMatchObject({ version: "1.1.2", compatible: true, integrityReady: true, signatureReady: true, isNewer: true });
+      expect(result.latest).toMatchObject({ version: "1.1.3", compatible: true, integrityReady: true, signatureReady: true, isNewer: true });
       const cached = database.sqlite.prepare("SELECT value FROM system_settings WHERE key='update.release.v1'").get() as { value: string };
       expect(JSON.parse(cached.value).asset.sha256).toBe(digest);
     } finally {
diff --git a/uninstall.sh b/uninstall.sh
new file mode 100755
index 0000000..1e33cab
--- /dev/null
+++ b/uninstall.sh
@@ -0,0 +1,473 @@
+#!/usr/bin/env bash
+set -Eeuo pipefail
+
+# TallyNote native uninstaller. The default operation removes only the
+# application and service integration; the database and attachments stay in
+# place until --purge-data --yes is explicitly requested.
+PATH=/usr/sbin:/usr/bin:/sbin:/bin:/usr/local/bin
+export PATH
+umask 077
+
+TEST_MODE=${TALLYNOTE_UNINSTALL_TEST_MODE:-false}
+TEST_ROOT=${TALLYNOTE_UNINSTALL_ROOT:-}
+PREFIX=${TALLYNOTE_PREFIX:-/opt/tallynote}
+DATA_DIR=${TALLYNOTE_DATA_DIR:-/var/lib/tallynote}
+CONFIG_DIR=${TALLYNOTE_CONFIG_DIR:-/etc/tallynote}
+UNIT_DIR=${TALLYNOTE_SYSTEMD_UNIT_DIR:-/etc/systemd/system}
+SBIN_DIR=${TALLYNOTE_SBIN_DIR:-/usr/local/sbin}
+LIBEXEC_DIR=${TALLYNOTE_LIBEXEC_DIR:-/usr/local/libexec}
+SYSTEMCTL_BIN=systemctl
+SYSTEMCTL_AVAILABLE=0
+PURGE_DATA=0
+PURGE_CONFIG=0
+YES=0
+DRY_RUN=0
+FORCE=0
+EXPLICIT_PREFIX=0
+EXPLICIT_DATA=0
+EXPLICIT_CONFIG=0
+
+die() { printf 'tallynote uninstaller: %s\n' "$*" >&2; exit 1; }
+log() { printf 'tallynote uninstaller: %s\n' "$*"; }
+
+usage() {
+  cat <<'EOF'
+Usage: tallynote-uninstall [--yes] [--purge-data] [--purge-config]
+                           [--dry-run] [--force]
+                           [--prefix PATH] [--data-dir PATH] [--config-dir PATH]
+
+By default, remove the TallyNote release tree, systemd units, update helpers,
+and known configuration files. The database, attachments, staging, exports,
+update queue, and update backups are preserved. Data removal requires both
+--purge-data and --yes. --force is only for an operator who has verified that
+no update is in progress; it overrides the pending-update guard.
+EOF
+}
+
+is_true() { [[ "$1" == true || "$1" == 1 ]]; }
+
+if [[ "$TEST_MODE" != true && "$TEST_MODE" != false && "$TEST_MODE" != 1 && "$TEST_MODE" != 0 ]]; then
+  die 'TALLYNOTE_UNINSTALL_TEST_MODE must be true or false'
+fi
+if [[ "$TEST_MODE" == 1 ]]; then TEST_MODE=true; fi
+if [[ "$TEST_MODE" == 0 ]]; then TEST_MODE=false; fi
+
+while (($#)); do
+  case "$1" in
+    --yes) YES=1 ;;
+    --purge-data) PURGE_DATA=1 ;;
+    --purge-config) PURGE_CONFIG=1 ;;
+    --dry-run) DRY_RUN=1 ;;
+    --force) FORCE=1 ;;
+    --prefix) PREFIX=${2:?missing value for --prefix}; EXPLICIT_PREFIX=1; shift ;;
+    --data-dir) DATA_DIR=${2:?missing value for --data-dir}; EXPLICIT_DATA=1; shift ;;
+    --config-dir) CONFIG_DIR=${2:?missing value for --config-dir}; EXPLICIT_CONFIG=1; shift ;;
+    -h|--help) usage; exit 0 ;;
+    *) die "unknown option: $1" ;;
+  esac
+  shift
+done
+
+if [[ "$TEST_MODE" == true ]]; then
+  [[ -n "$TEST_ROOT" ]] || die 'test mode requires TALLYNOTE_UNINSTALL_ROOT'
+  [[ "$TEST_ROOT" = /* && "$TEST_ROOT" != *'..'* && "$TEST_ROOT" != *'//'* && "$TEST_ROOT" != *$'\n'* && "$TEST_ROOT" != *$'\r'* ]] || die 'test root is invalid'
+  (( EXPLICIT_PREFIX )) || PREFIX=${TALLYNOTE_PREFIX:-$TEST_ROOT/opt/tallynote}
+  (( EXPLICIT_DATA )) || DATA_DIR=${TALLYNOTE_DATA_DIR:-$TEST_ROOT/var/lib/tallynote}
+  (( EXPLICIT_CONFIG )) || CONFIG_DIR=${TALLYNOTE_CONFIG_DIR:-$TEST_ROOT/etc/tallynote}
+  UNIT_DIR=${TALLYNOTE_SYSTEMD_UNIT_DIR:-$TEST_ROOT/etc/systemd/system}
+  SBIN_DIR=${TALLYNOTE_SBIN_DIR:-$TEST_ROOT/usr/local/sbin}
+  LIBEXEC_DIR=${TALLYNOTE_LIBEXEC_DIR:-$TEST_ROOT/usr/local/libexec}
+  SYSTEMCTL_BIN=${TALLYNOTE_SYSTEMCTL_BIN:-systemctl}
+fi
+
+stat_uid() { stat -c '%u' "$1" 2>/dev/null || stat -f '%u' "$1"; }
+stat_mode() { stat -c '%a' "$1" 2>/dev/null || stat -f '%Lp' "$1"; }
+stat_mode_bits() {
+  local mode
+  mode=$(stat_mode "$1")
+  [[ "$mode" =~ ^[0-7]+$ ]] || die "无法读取路径权限：$1"
+  printf '%d' "$((8#$mode))"
+}
+
+allowed_owner() {
+  local path=$1 uid
+  uid=$(stat_uid "$path")
+  if [[ "$TEST_MODE" == true ]]; then
+    [[ "$uid" == "$(id -u)" || "$uid" == 0 ]]
+  else
+    [[ "$uid" == 0 ]]
+  fi
+}
+
+allowed_data_owner() {
+  local path=$1 uid tallynote_uid
+  uid=$(stat_uid "$path")
+  if [[ "$TEST_MODE" == true ]]; then
+    [[ "$uid" == "$(id -u)" || "$uid" == 0 ]]
+    return
+  fi
+  [[ "$uid" == 0 ]] && return 0
+  tallynote_uid=$(id -u tallynote 2>/dev/null || true)
+  [[ -n "$tallynote_uid" && "$uid" == "$tallynote_uid" ]]
+}
+
+validate_path_value() {
+  local value=$1 label=$2
+  [[ "$value" = /* && "$value" != *$'\n'* && "$value" != *$'\r'* ]] || die "$label 必须是绝对路径"
+  [[ "$value" =~ ^/[A-Za-z0-9._/-]+$ && "$value" != *"//"* && "$value" != *"/../"* && "$value" != */.. && "$value" != *"/./"* && "$value" != */. && "$value" != / && "$value" != */ ]] || die "$label 包含不受支持的路径字符"
+  case "$value" in
+    /opt|/var|/etc|/usr|/usr/local|/bin|/sbin|/home|/root|/tmp) die "$label 不能指向系统顶层目录" ;;
+  esac
+}
+
+validate_parent_chain() {
+  local target=$1 current=/ component relative
+  relative=${target#/}
+  IFS='/' read -r -a _parts <<< "$relative"
+  for component in "${_parts[@]}"; do
+    [[ -n "$component" ]] || continue
+    current="${current%/}/$component"
+    if [[ -L "$current" ]]; then die "路径不能包含符号链接：$current"; fi
+    if [[ -e "$current" ]]; then
+      [[ -d "$current" ]] || die "路径不是目录：$current"
+      allowed_owner "$current" || die "路径目录的所有者不受信任：$current"
+      local mode_bits
+      mode_bits=$(stat_mode_bits "$current")
+      (( (mode_bits & 18) == 0 || (mode_bits & 512) != 0 )) || die "路径目录权限过宽：$current"
+    fi
+  done
+}
+
+validate_target() {
+  local target=$1 label=$2 owner_check=allowed_owner
+  [[ "${3:-}" == data ]] && owner_check=allowed_data_owner
+  validate_path_value "$target" "$label"
+  validate_parent_chain "$target"
+  if [[ -e "$target" || -L "$target" ]]; then
+    "$owner_check" "$target" || die "$label 的所有者不受信任：$target"
+  fi
+}
+
+read_env_value() {
+  local file=$1 key=$2
+  sed -n "s/^${key}=//p" "$file" | head -n 1
+}
+
+env_key_count() {
+  local file=$1 key=$2
+  awk -v key="$key" 'index($0, key "=") == 1 { count += 1 } END { print count + 0 }' "$file"
+}
+
+load_config() {
+  local env_file=$CONFIG_DIR/tallynote.env value key count
+  [[ -e "$env_file" || -L "$env_file" ]] || return 0
+  [[ -f "$env_file" && ! -L "$env_file" ]] || die '环境文件不是普通文件'
+  allowed_owner "$env_file" || die '环境文件的所有者不受信任'
+  local mode_bits
+  mode_bits=$(stat_mode_bits "$env_file")
+  (( (mode_bits & 18) == 0 )) || die '环境文件不能被组或其他用户写入'
+  for key in TALLYNOTE_INSTALL_PREFIX TALLYNOTE_DATA_DIR; do
+    count=$(env_key_count "$env_file" "$key")
+    [[ "$count" == 0 || "$count" == 1 ]] || die "环境文件包含重复配置：$key"
+  done
+  if (( ! EXPLICIT_PREFIX )); then
+    value=$(read_env_value "$env_file" TALLYNOTE_INSTALL_PREFIX)
+    [[ -z "$value" ]] || PREFIX=$value
+  fi
+  if (( ! EXPLICIT_DATA )); then
+    value=$(read_env_value "$env_file" TALLYNOTE_DATA_DIR)
+    [[ -z "$value" ]] || DATA_DIR=$value
+  fi
+}
+
+path_inside() {
+  local child=$1 parent=$2
+  [[ "$child" == "$parent"/* ]]
+}
+
+assert_disjoint_paths() {
+  local left left_label right right_label
+  local -a labels=(prefix data config unit sbin libexec)
+  for left_label in "${labels[@]}"; do
+    case "$left_label" in
+      prefix) left=$PREFIX ;;
+      data) left=$DATA_DIR ;;
+      config) left=$CONFIG_DIR ;;
+      unit) left=$UNIT_DIR ;;
+      sbin) left=$SBIN_DIR ;;
+      libexec) left=$LIBEXEC_DIR ;;
+    esac
+    for right_label in "${labels[@]}"; do
+      [[ "$left_label" == "$right_label" ]] && continue
+      case "$right_label" in
+        prefix) right=$PREFIX ;;
+        data) right=$DATA_DIR ;;
+        config) right=$CONFIG_DIR ;;
+        unit) right=$UNIT_DIR ;;
+        sbin) right=$SBIN_DIR ;;
+        libexec) right=$LIBEXEC_DIR ;;
+      esac
+      if [[ "$left" == "$right" ]] || path_inside "$left" "$right" || path_inside "$right" "$left"; then
+        die "卸载目录不能互相嵌套：$left 与 $right"
+      fi
+    done
+  done
+}
+
+assert_test_scope() {
+  [[ "$TEST_MODE" == true ]] || return 0
+  [[ -d "$TEST_ROOT" && ! -L "$TEST_ROOT" ]] || die 'test root must be an existing directory'
+  validate_parent_chain "$TEST_ROOT"
+  allowed_owner "$TEST_ROOT" || die 'test root owner is not trusted'
+  local value label
+  for label in PREFIX DATA_DIR CONFIG_DIR UNIT_DIR SBIN_DIR LIBEXEC_DIR; do
+    case "$label" in
+      PREFIX) value=$PREFIX ;;
+      DATA_DIR) value=$DATA_DIR ;;
+      CONFIG_DIR) value=$CONFIG_DIR ;;
+      UNIT_DIR) value=$UNIT_DIR ;;
+      SBIN_DIR) value=$SBIN_DIR ;;
+      LIBEXEC_DIR) value=$LIBEXEC_DIR ;;
+    esac
+    [[ "$value" == "$TEST_ROOT"/* ]] || die "test mode path escapes TALLYNOTE_UNINSTALL_ROOT: $value"
+  done
+}
+
+managed_file() {
+  local target=$1 label=$2
+  case "$label" in
+    service\ unit|updater\ unit|path\ unit|update\ helper|update\ runner|uninstaller)
+      grep -Eiq 'tallynote|TallyNote' "$target" || return 1
+      if [[ "$label" == 'path unit' ]]; then
+        grep -Fq "$DATA_DIR" "$target" || return 1
+      elif [[ "$label" == *unit ]]; then
+        grep -Fq "$PREFIX" "$target" || return 1
+      else
+        grep -Eq 'TALLYNOTE_INSTALL_PREFIX|/opt/tallynote' "$target" || return 1
+      fi
+      ;;
+    environment\ file)
+      grep -q '^TALLYNOTE_INSTALL_PREFIX=' "$target" || return 1
+      grep -q '^TALLYNOTE_DATA_DIR=' "$target" || return 1
+      [[ "$(read_env_value "$target" TALLYNOTE_INSTALL_PREFIX)" == "$PREFIX" ]] || return 1
+      [[ "$(read_env_value "$target" TALLYNOTE_DATA_DIR)" == "$DATA_DIR" ]] || return 1
+      ;;
+    update\ public\ key)
+      [[ -f "$CONFIG_DIR/tallynote.env" ]] || return 1
+      [[ "$(read_env_value "$CONFIG_DIR/tallynote.env" TALLYNOTE_UPDATE_PUBLIC_KEY_FILE)" == "$target" ]] || return 1
+      ;;
+    *) return 0 ;;
+  esac
+}
+
+validate_release_tree() {
+  local tree=$1 owner_check=${2:-allowed_owner}
+  [[ -d "$tree" && ! -L "$tree" ]] || die "发布目录无效：$tree"
+  "$owner_check" "$tree" || die "发布目录的所有者不受信任：$tree"
+  if find "$tree" -type l -print -quit | grep -q .; then
+    die "发布目录包含符号链接：$tree"
+  fi
+  if find "$tree" ! -type d ! -type f -print -quit | grep -q .; then
+    die "发布目录包含不支持的文件类型：$tree"
+  fi
+  local node mode_bits
+  while IFS= read -r node; do
+    "$owner_check" "$node" || die "发布目录节点的所有者不受信任：$node"
+    mode_bits=$(stat_mode_bits "$node")
+    (( (mode_bits & 18) == 0 )) || die "发布目录节点权限过宽：$node"
+  done < <(find "$tree" -print)
+}
+
+pending_update() {
+  [[ -e "$PREFIX/.update-state" || -L "$PREFIX/.update-state" || -e "$DATA_DIR/update-request.json" || -L "$DATA_DIR/update-request.json" ]]
+}
+
+run_systemctl() {
+  (( DRY_RUN )) && return 0
+  if [[ "$SYSTEMCTL_BIN" == */* ]]; then
+    [[ -x "$SYSTEMCTL_BIN" ]] || return 0
+  else
+    command -v "$SYSTEMCTL_BIN" >/dev/null 2>&1 || return 0
+  fi
+  "$SYSTEMCTL_BIN" "$@"
+}
+
+stop_services() {
+  local unit active status
+  if (( DRY_RUN )); then
+    log 'dry-run: would stop/disable systemd units in path -> updater -> app order'
+    return 0
+  fi
+  if (( ! SYSTEMCTL_AVAILABLE )); then
+    for unit in tallynote-update.path tallynote-update.service tallynote.service; do
+      [[ ! -e "$UNIT_DIR/$unit" ]] || die 'systemctl 不可用，无法安全停止已安装服务'
+    done
+    return 0
+  fi
+  for unit in tallynote-update.path tallynote-update.service tallynote.service; do
+    active=0
+    if run_systemctl is-active --quiet "$unit" >/dev/null 2>&1; then
+      active=1
+    else
+      status=$?
+      case "$status" in
+        3|4) ;;
+        *) die "无法读取服务状态：$unit" ;;
+      esac
+    fi
+    if (( active )); then
+      run_systemctl stop "$unit" || die "无法停止服务：$unit"
+    fi
+    if [[ -e "$UNIT_DIR/$unit" ]]; then
+      run_systemctl disable "$unit" >/dev/null 2>&1 || die "无法禁用服务：$unit"
+    fi
+  done
+  run_systemctl daemon-reload >/dev/null 2>&1 || die 'systemd daemon-reload 失败'
+}
+
+validate_systemctl() {
+  local resolved uid mode_bits
+  if [[ "$TEST_MODE" == true ]]; then
+    if [[ "$SYSTEMCTL_BIN" == */* && -x "$SYSTEMCTL_BIN" ]]; then
+      SYSTEMCTL_AVAILABLE=1
+    fi
+    return 0
+  fi
+  resolved=$(command -v systemctl 2>/dev/null || true)
+  if [[ -z "$resolved" ]]; then
+    SYSTEMCTL_AVAILABLE=0
+    return 0
+  fi
+  [[ -x "$resolved" && ! -L "$resolved" ]] || die 'systemctl 必须是可信的普通可执行文件'
+  uid=$(stat_uid "$resolved")
+  mode_bits=$(stat_mode_bits "$resolved")
+  [[ "$uid" == 0 && $((mode_bits & 18)) -eq 0 ]] || die 'systemctl 必须由 root 拥有且不可被其他用户写入'
+  SYSTEMCTL_BIN=$resolved
+  SYSTEMCTL_AVAILABLE=1
+}
+
+remove_file_if_owned() {
+  local target=$1 label=$2
+  [[ -e "$target" || -L "$target" ]] || return 0
+  if [[ -L "$target" || ! -f "$target" ]]; then
+    log "warning: 保留非普通文件：$target"
+    return 0
+  fi
+  if ! allowed_owner "$target"; then
+    log "warning: 保留非本安装创建的文件：$target"
+    return 0
+  fi
+  if ! managed_file "$target" "$label"; then
+    log "warning: 保留内容不匹配的文件：$target"
+    return 0
+  fi
+  if (( DRY_RUN )); then
+    log "dry-run: remove $label $target"
+  else
+    rm -f -- "$target"
+  fi
+}
+
+remove_tree() {
+  local target=$1 label=$2 owner_check=${3:-allowed_owner}
+  [[ -e "$target" || -L "$target" ]] || return 0
+  [[ -d "$target" && ! -L "$target" ]] || die "$label 不是安全目录：$target"
+  "$owner_check" "$target" || die "$label 的所有者不受信任：$target"
+  validate_release_tree "$target" "$owner_check"
+  if (( DRY_RUN )); then
+    log "dry-run: remove $label $target"
+  else
+    rm -rf -- "$target"
+  fi
+}
+
+remove_prefix() {
+  local current=$PREFIX/current current_target releases=$PREFIX/releases
+  if [[ -L "$current" ]]; then
+    current_target=$(readlink "$current")
+    [[ "$current_target" = "$PREFIX/releases/"* && "$current_target" != *'..'* ]] || die 'current 符号链接指向安装目录之外'
+    [[ -d "$current_target" && ! -L "$current_target" ]] || die 'current 目标不是安全目录'
+    if (( DRY_RUN )); then
+      log "dry-run: remove current link $current"
+    else
+      rm -f -- "$current"
+    fi
+  elif [[ -e "$current" ]]; then
+    log "warning: 保留非符号链接 current：$current"
+  fi
+  remove_tree "$releases" 'releases'
+  remove_tree "$PREFIX/.update-work" 'update work'
+  remove_file_if_owned "$PREFIX/.update-state" 'update state'
+  if [[ -d "$PREFIX" && ! -L "$PREFIX" ]]; then
+    allowed_owner "$PREFIX" || die "安装目录的所有者不受信任：$PREFIX"
+    if (( DRY_RUN )); then
+      log "dry-run: remove empty install directory if empty: $PREFIX"
+    else
+      rmdir -- "$PREFIX" 2>/dev/null || true
+    fi
+  fi
+}
+
+remove_config() {
+  remove_file_if_owned "$CONFIG_DIR/update-signing-key.pub" 'update public key'
+  remove_file_if_owned "$CONFIG_DIR/tallynote.env" 'environment file'
+  if (( PURGE_CONFIG )) && [[ -d "$CONFIG_DIR" && ! -L "$CONFIG_DIR" ]]; then
+    allowed_owner "$CONFIG_DIR" || die '配置目录的所有者不受信任'
+    if (( DRY_RUN )); then log "dry-run: remove config directory if safe: $CONFIG_DIR"; else rmdir -- "$CONFIG_DIR" 2>/dev/null || true; fi
+  fi
+}
+
+remove_data() {
+  local backup_dir
+  backup_dir=$(dirname -- "$DATA_DIR")/tallynote-backups
+  if (( PURGE_DATA )); then
+    (( YES )) || die '--purge-data 必须同时提供 --yes'
+    remove_tree "$DATA_DIR" 'data' allowed_data_owner
+    remove_tree "$backup_dir" 'backup data'
+  else
+    log "保留数据目录：$DATA_DIR"
+    if [[ -d "$backup_dir" ]]; then
+      log "保留备份目录：$backup_dir"
+    fi
+  fi
+  return 0
+}
+
+main() {
+  if [[ "$TEST_MODE" != true ]]; then
+    [[ $EUID -eq 0 ]] || die '卸载必须以 root 运行（请使用 sudo）'
+  fi
+  if (( PURGE_DATA && ! YES )); then
+    die '--purge-data 必须同时提供 --yes'
+  fi
+  validate_path_value "$CONFIG_DIR" '配置目录'
+  validate_target "$CONFIG_DIR" '配置目录'
+  assert_test_scope
+  load_config
+  validate_target "$PREFIX" '安装目录'
+  validate_target "$DATA_DIR" '数据目录' data
+  validate_target "$CONFIG_DIR" '配置目录'
+  validate_target "$UNIT_DIR" 'systemd 单元目录'
+  validate_target "$SBIN_DIR" 'sbin 目录'
+  validate_target "$LIBEXEC_DIR" 'libexec 目录'
+  assert_test_scope
+  assert_disjoint_paths
+  validate_systemctl
+  if (( ! FORCE )) && pending_update; then
+    die '检测到未完成的更新状态；确认更新已停止后使用 --force 重试'
+  fi
+  log "target: prefix=$PREFIX data=$DATA_DIR config=$CONFIG_DIR"
+  stop_services
+  remove_prefix
+  remove_file_if_owned "$UNIT_DIR/tallynote.service" 'service unit'
+  remove_file_if_owned "$UNIT_DIR/tallynote-update.service" 'updater unit'
+  remove_file_if_owned "$UNIT_DIR/tallynote-update.path" 'path unit'
+  remove_file_if_owned "$SBIN_DIR/tallynote-update" 'update helper'
+  remove_file_if_owned "$LIBEXEC_DIR/tallynote-update-runner" 'update runner'
+  remove_file_if_owned "$SBIN_DIR/tallynote-uninstall" 'uninstaller'
+  remove_config
+  remove_data
+  log 'uninstall complete'
+}
+
+main "$@"