feat(glab-plugin): enhance GitLab CLI support with additional helpers and aliases

- Added merge request helpers:
  - `glmr-checkout`: checkout MR branch locally
  - `glmr-merge`: merge MR and optionally remove source branch
  - `glmr-list`: list MRs assigned to the current user

- Added issue helpers:
  - `glissue-close`: close an issue
  - `glissue-list`: list open issues assigned to the current user

- Added CI/CD helpers:
  - `glci-retry`: retry a failed pipeline
  - `glci-latest`: view the latest pipeline
  - `glci-status`: open pipeline in browser

- Added repository helpers:
  - `glrepo-clone`: clone a repository
  - `glrepo-list`: list repositories user is a member of
  - `glrepo-open`: open repository in browser
  - `glrepo-starred`: list starred repositories

- Added release helpers:
  - `glrelease-create`: create a release with title and tag

- Added search helper:
  - `glsearch`: search for merge requests and issues by keyword

- Updated README.md:
  - Documented new aliases and helper functions
  - Added usage examples and environment variable notes

This PR improves developer productivity by providing convenient shortcuts and web integrations for managing GitLab repositories, merge requests, issues, pipelines, and releases directly from the terminal.

Closes #13054

plugins/glab/README.md

@@ -0,0 +1,94 @@
+# glab plugin
+
+This plugin adds support for the [GitLab CLI (`glab`)](https://gitlab.com/gitlab-org/cli), a tool to interact with GitLab from the terminal.
+
+## Features
+
+- **Shell completion**: enables `zsh` completions for `glab` automatically if it is installed.  
+- **Environment setup**: loads `GITLAB_HOST` and `GITLAB_TOKEN` from `~/.netrc` if they are not already set.  
+- **Aliases**: provides convenient shortcuts for common GitLab CLI commands.  
+- **Helper functions**: adds extra functions for common GitLab workflows, including merge requests, issues, CI/CD pipelines, repositories, and releases.  
+
+## Aliases
+
+| Alias       | Command           | Description                     |
+|------------ |------------------ |-------------------------------- |
+| `gl`        | `glab`            | Shortcut for `glab`             |
+| `glmr`      | `glab mr`         | Manage merge requests           |
+| `glissue`   | `glab issue`      | Manage issues                   |
+| `glrepo`    | `glab repo`       | Manage repositories             |
+| `glci`      | `glab ci`         | Manage CI pipelines             |
+| `glprj`     | `glab project`    | Manage projects                 |
+| `glrelease` | `glab release`    | Manage releases                 |
+| `gli`       | `glab incident`   | Manage incidents                |
+
+## Helper functions
+
+### Merge Requests
+- `glmr-open [<MR>]`  
+  Opens a merge request in the browser. If `<MR>` is not specified, opens the current branch MR.
+
+- `glmr-checkout <MR>`  
+  Checks out the merge request branch locally.
+
+- `glmr-merge <MR>`  
+  Merges a merge request and optionally removes the source branch.
+
+- `glmr-list [<args>]`  
+  Lists merge requests assigned to you. Additional `glab mr list` arguments can be passed.
+
+### Issues
+- `glissue-new [<title>]`  
+  Creates a new issue. If a title is provided, it is used; otherwise an interactive prompt is opened.
+
+- `glissue-close <issue>`  
+  Closes the specified issue.
+
+- `glissue-list [<args>]`  
+  Lists open issues assigned to you. Additional `glab issue list` arguments can be passed.
+
+### CI/CD
+- `glci-status [<args>]`  
+  Opens the current CI pipeline status in the browser.
+
+- `glci-retry <pipeline>`  
+  Retries the specified pipeline.
+
+- `glci-latest`  
+  Shows the latest pipeline.
+
+### Repositories
+- `glrepo-clone <project>`  
+  Clones a repository.
+
+- `glrepo-list [<args>]`  
+  Lists all repositories you are a member of.
+
+- `glrepo-open <project>`  
+  Opens a repository in the browser.
+
+- `glrepo-starred [<args>]`  
+  Lists your starred repositories.
+
+### Releases
+- `glrelease-create "<title>" "<tag>"`  
+  Creates a new release with the given title and tag.
+
+### Search
+- `glsearch <keyword>`  
+  Searches for merge requests and issues matching the keyword.
+
+## Environment variables
+
+The plugin attempts to set the following variables if they are not already defined:
+
+- `GITLAB_HOST` — taken from the first `machine` entry in `~/.netrc`.  
+- `GITLAB_TOKEN` — the corresponding `password` from `~/.netrc`.  
+
+## Usage
+
+1. Install [`glab`](https://gitlab.com/gitlab-org/cli#installation).  
+2. Enable the plugin in your `.zshrc`:
+
+```zsh
+plugins=(git glab)