feat(go): add zcp - copy tool with progress bar

.github/workflows/zcp-golangci-lint.yml

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+../../go/tools/zcp/.github/workflows/zcp-golangci-lint.yml

.github/workflows/zcp-tests.yml

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+../../go/tools/zcp/.github/workflows/zcp-tests.yml

go/tools/zcp/.github/workflows/zcp-golangci-lint.yml

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+name: Format & Lint
+
+on:
+  push:
+    paths: &paths
+      - "go/tools/zcp/**/*.go"
+      - "go/tools/zcp/go.mod"
+      - "go/tools/zcp/go.sum"
+      - "go/tools/zcp/.golangci.yml"
+      - "go/tools/zcp/.github/workflows/zcp-golangci-lint.yml"
+      - "go/tools/zcp/.github/workflows/zcp-tests.yml"
+      - ".github/workflows/zcp-golangci-lint.yml"
+      - ".github/workflows/zcp-tests.yml"
+  pull_request:
+    paths: *paths
+  workflow_dispatch:
+
+concurrency:
+  group: zcp-format-lint-${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  format:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Setup Go with module cache
+        uses: actions/setup-go@v6
+        with:
+          go-version-file: go/tools/zcp/go.mod
+          cache: true
+          cache-dependency-path: |
+            go/tools/zcp/go.mod
+            go/tools/zcp/go.sum
+
+      - name: Cache golangci-lint data
+        uses: actions/cache@v5
+        with:
+          path: ~/.cache/golangci-lint
+          key: ${{ runner.os }}-golangci-format-${{ hashFiles('go/tools/zcp/go.mod', 'go/tools/zcp/go.sum', 'go/tools/zcp/.golangci.yml') }}
+          restore-keys: |
+            ${{ runner.os }}-golangci-format-
+
+      - name: Check formatting via golangci-lint
+        uses: golangci/golangci-lint-action@v9
+        with:
+          version: latest
+          working-directory: go/tools/zcp
+          args: fmt --diff --timeout=5m ./...
+          skip-cache: false
+
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Setup Go with module cache
+        uses: actions/setup-go@v6
+        with:
+          go-version-file: go/tools/zcp/go.mod
+          cache: true
+          cache-dependency-path: |
+            go/tools/zcp/go.mod
+            go/tools/zcp/go.sum
+
+      - name: Cache golangci-lint data
+        uses: actions/cache@v5
+        with:
+          path: ~/.cache/golangci-lint
+          key: ${{ runner.os }}-golangci-${{ hashFiles('go/tools/zcp/go.mod', 'go/tools/zcp/go.sum', 'go/tools/zcp/.golangci.yml') }}
+          restore-keys: |
+            ${{ runner.os }}-golangci-
+
+      - name: Run golangci-lint
+        uses: golangci/golangci-lint-action@v9
+        with:
+          version: latest
+          working-directory: go/tools/zcp
+          args: --timeout=5m ./...
+          skip-cache: false

go/tools/zcp/.github/workflows/zcp-tests.yml

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+name: Tests
+
+on:
+  push:
+    paths: &paths
+      - "go/tools/zcp/**/*.go"
+      - "go/tools/zcp/go.mod"
+      - "go/tools/zcp/go.sum"
+      - "go/tools/zcp/.github/workflows/zcp-tests.yml"
+      - "go/tools/zcp/.github/workflows/zcp-golangci-lint.yml"
+      - ".github/workflows/zcp-tests.yml"
+      - ".github/workflows/zcp-golangci-lint.yml"
+  pull_request:
+    paths: *paths
+  workflow_dispatch:
+
+concurrency:
+  group: zcp-tests-${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Setup Go with module cache
+        uses: actions/setup-go@v6
+        with:
+          go-version-file: go/tools/zcp/go.mod
+          cache: true
+          cache-dependency-path: |
+            go/tools/zcp/go.mod
+            go/tools/zcp/go.sum
+
+      - name: Run tests
+        working-directory: go/tools/zcp
+        run: go test ./...

go/tools/zcp/.golangci.yml

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+version: "2"
+
+run:
+  timeout: 5m
+  tests: true
+
+linters:
+  disable-all: true
+  enable:
+    - errcheck
+    - govet
+    - ineffassign
+    - staticcheck
+    - unused
+
+formatters:
+  enable:
+    - gofumpt
+    - goimports
+    - golines

go/tools/zcp/README.md

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+# zcp
+
+Like `cp`, but with a progress bar. The `z` is there because I liked it and to avoid name collisions.
+
+Inspired by the original `gcp` utility:
+https://manpages.ubuntu.com/manpages/focal/man1/gcp.1.html
+
+## Features
+
+- Copy files and directories
+- Recursive directory copy (`-r`)
+- Per-copy progress bar with:
+  - percent complete
+  - bytes copied / total bytes
+  - transfer speed
+  - ETA
+- Optional metadata preservation (`-p` mode + mtime)
+- Optional overwrite (`-f`)
+- Optional verbose output (`-v`) to print created file names
+
+## Usage
+
+```bash
+zcp [options] SOURCE... DEST
+```
+
+### Options
+
+- `-r`, `--recursive`: copy directories recursively
+- `-f`, `--force`: overwrite destination files
+- `-p`, `--preserve`: preserve mode and modification time
+- `-q`, `--quiet`: disable progress output
+- `-v`, `--verbose`: print created file names
+- `--buffer-size`: copy buffer size in bytes (default `1048576`)
+
+### Examples
+
+Copy a single file:
+
+```bash
+zcp movie.mkv /mnt/backup/movie.mkv
+```
+
+Copy a directory recursively:
+
+```bash
+zcp -r photos /mnt/backup/
+```
+
+Copy multiple sources into an existing destination directory:
+
+```bash
+zcp -r folder_a folder_b file.txt /mnt/backup/
+```
+
+Overwrite existing files:
+
+```bash
+zcp -f large.iso /mnt/backup/large.iso
+```
+
+Preserve source mode + mtime:
+
+```bash
+zcp -p -r assets ./assets-copy
+```
+
+Disable progress output:
+
+```bash
+zcp -q -r logs /tmp/logs-copy
+```
+
+Verbose file listing:
+
+```bash
+zcp -v -r photos /mnt/backup/
+```
+
+## Build
+
+From this directory:
+
+```bash
+mkdir -p bin
+go build -o bin/zcp ./cmd/zcp
+```
+
+### Cross-compile
+
+Linux:
+
+```bash
+mkdir -p bin
+GOOS=linux GOARCH=amd64 go build -o bin/zcp-linux-amd64 ./cmd/zcp
+```
+
+Windows:
+
+```bash
+mkdir -p bin
+GOOS=windows GOARCH=amd64 go build -o bin/zcp-windows-amd64.exe ./cmd/zcp
+```
+
+## Notes
+
+- Symbolic links are currently not copied.
+- For multiple sources, destination must already exist as a directory.