docs: Document SHA-256 checksum verification for the runpodctl install script and self-update

runpodctl/overview.mdx

@@ -1,12 +1,12 @@
 ---
 title: "Overview"
 sidebarTitle: "Overview"
 description: "Use Runpod CLI to manage Pods, Serverless endpoints, templates, and more from your local machine. Review commands and usage guidance for the Runpod CLI."
 ---
 
 import { PodsTooltip, PodTooltip } from "/snippets/tooltips.jsx";
 
 Runpod CLI is an [open source](https://github.com/runpod/runpodctl) command-line tool for managing your Runpod resources from your local machine. You can manage Pods, Serverless endpoints, templates, network volumes, and models, transfer files between your system and Runpod, diagnose issues, and view account information.
 
 ## Quick start
 
@@ -20,7 +20,7 @@
 runpodctl pod list                  # List your Pods
 ```
 
 ## Install Runpod CLI locally
 
 Every <PodTooltip /> you deploy comes preinstalled with `runpodctl` and a Pod-scoped API key. You can also install it on your local machine to manage resources remotely.
 
@@ -45,6 +45,10 @@
 
 The script installs the latest version to `/usr/local/bin` when run as root, or to `~/.local/bin` for non-root users. If you don't have root access, the script displays instructions for adding `runpodctl` to your PATH.
 
+<Note>
+The install script verifies the downloaded release against its SHA-256 checksum before installing, so it needs a checksum tool to be present: `sha256sum` on Linux or `shasum` on macOS. These are preinstalled in most environments, but on minimal images without one the install aborts.
+</Note>
+
 </Tab>
 
 <Tab title="macOS">
@@ -145,7 +149,7 @@
 runpodctl doctor
 ```
 
 This command guides you through first-time setup, including API key configuration and SSH key setup.
 
 Alternatively, you can manually configure your API key:
 
@@ -158,7 +162,7 @@
 saved apiKey into config file: /Users/runpod/.runpod/config.toml
 ```
 
 ### Step 3: Verify installation
 
 To verify that `runpodctl` installed successfully, run this command:
 
@@ -166,7 +170,7 @@
 runpodctl version
 ```
 
 You should see which version is installed:
 
 ```bash
 runpodctl v2.0
@@ -174,11 +178,11 @@
 
 ## Command groups
 
 Runpod CLI organizes commands into groups based on the resource type:
 
 | Command | Alias | Description |
 |---------|-------|-------------|
 | `runpodctl pod` | | Manage Pods (create, list, start, stop, delete) |
 | `runpodctl serverless` | `sls` | Manage Serverless endpoints |
 | `runpodctl template` | `tpl` | List, search, and manage templates |
 | `runpodctl hub` | | Browse and deploy from the Runpod Hub |
@@ -192,7 +196,7 @@
 
 ## Help and reference
 
 Learn how to use Runpod CLI commands by browsing the CLI reference using the sidebar to the left, or by running the `help` command:
 
 ```bash
 runpodctl help
@@ -211,6 +215,6 @@
 runpodctl completion
 ```
 
 This command auto-detects your shell and adds the appropriate source command to your shell configuration file (`~/.bashrc` or `~/.zshrc`). The command is idempotent—running it again skips installation if completion is already configured.
 
 Restart your shell or source the configuration file for changes to take effect.

runpodctl/reference/runpodctl-update.mdx

@@ -1,9 +1,9 @@
 ---
 title: "update"
 sidebarTitle: "update"
 ---
 
 Update `runpodctl` to the latest version to access new features and bug fixes.
 
 <RequestExample>
 ```bash Command
@@ -13,7 +13,7 @@
 
 ## Description
 
-The `update` command downloads and installs the latest version of `runpodctl`. After updating, verify the installation with [`runpodctl version`](/runpodctl/reference/runpodctl-version).
+The `update` command downloads the latest version of `runpodctl` and verifies it against its SHA-256 checksum before replacing the installed binary. Verification always runs. If it fails, the update aborts and leaves your existing binary in place. After updating, verify the installation with [`runpodctl version`](/runpodctl/reference/runpodctl-version).
 
 ## Related commands