docs: add Windows PowerShell equivalents for environments and scripting (#20333)

docs/reference/configuration.md

@@ -1332,7 +1332,8 @@ the `advanced.excludedEnvVars` setting in your `settings.json` file.
 - **`GEMINI_MODEL`**:
   - Specifies the default Gemini model to use.
   - Overrides the hardcoded default
-  - Example: `export GEMINI_MODEL="gemini-3-flash-preview"`
+  - Example: `export GEMINI_MODEL="gemini-3-flash-preview"` (Windows PowerShell:
+    `$env:GEMINI_MODEL="gemini-3-flash-preview"`)
 - **`GEMINI_CLI_IDE_PID`**:
   - Manually specifies the PID of the IDE process to use for integration. This
     is useful when running Gemini CLI in a standalone terminal while still
@@ -1344,12 +1345,14 @@ the `advanced.excludedEnvVars` setting in your `settings.json` file.
   - By default, this is the user's system home directory. The CLI will create a
     `.gemini` folder inside this directory.
   - Useful for shared compute environments or keeping CLI state isolated.
-  - Example: `export GEMINI_CLI_HOME="/path/to/user/config"`
+  - Example: `export GEMINI_CLI_HOME="/path/to/user/config"` (Windows
+    PowerShell: `$env:GEMINI_CLI_HOME="C:\path\to\user\config"`)
 - **`GOOGLE_API_KEY`**:
   - Your Google Cloud API key.
   - Required for using Vertex AI in express mode.
   - Ensure you have the necessary permissions.
-  - Example: `export GOOGLE_API_KEY="YOUR_GOOGLE_API_KEY"`.
+  - Example: `export GOOGLE_API_KEY="YOUR_GOOGLE_API_KEY"` (Windows PowerShell:
+    `$env:GOOGLE_API_KEY="YOUR_GOOGLE_API_KEY"`).
 - **`GOOGLE_CLOUD_PROJECT`**:
   - Your Google Cloud Project ID.
   - Required for using Code Assist or Vertex AI.
@@ -1360,18 +1363,23 @@ the `advanced.excludedEnvVars` setting in your `settings.json` file.
     you have `GOOGLE_CLOUD_PROJECT` set in your global environment in Cloud
     Shell, it will be overridden by this default. To use a different project in
     Cloud Shell, you must define `GOOGLE_CLOUD_PROJECT` in a `.env` file.
-  - Example: `export GOOGLE_CLOUD_PROJECT="YOUR_PROJECT_ID"`.
+  - Example: `export GOOGLE_CLOUD_PROJECT="YOUR_PROJECT_ID"` (Windows
+    PowerShell: `$env:GOOGLE_CLOUD_PROJECT="YOUR_PROJECT_ID"`).
 - **`GOOGLE_APPLICATION_CREDENTIALS`** (string):
   - **Description:** The path to your Google Application Credentials JSON file.
   - **Example:**
     `export GOOGLE_APPLICATION_CREDENTIALS="/path/to/your/credentials.json"`
+    (Windows PowerShell:
+    `$env:GOOGLE_APPLICATION_CREDENTIALS="C:\path\to\your\credentials.json"`)
 - **`GOOGLE_GENAI_API_VERSION`**:
   - Specifies the API version to use for Gemini API requests.
   - When set, overrides the default API version used by the SDK.
-  - Example: `export GOOGLE_GENAI_API_VERSION="v1"`
+  - Example: `export GOOGLE_GENAI_API_VERSION="v1"` (Windows PowerShell:
+    `$env:GOOGLE_GENAI_API_VERSION="v1"`)
 - **`OTLP_GOOGLE_CLOUD_PROJECT`**:
   - Your Google Cloud Project ID for Telemetry in Google Cloud
-  - Example: `export OTLP_GOOGLE_CLOUD_PROJECT="YOUR_PROJECT_ID"`.
+  - Example: `export OTLP_GOOGLE_CLOUD_PROJECT="YOUR_PROJECT_ID"` (Windows
+    PowerShell: `$env:OTLP_GOOGLE_CLOUD_PROJECT="YOUR_PROJECT_ID"`).
 - **`GEMINI_TELEMETRY_ENABLED`**:
   - Set to `true` or `1` to enable telemetry. Any other value is treated as
     disabling it.
@@ -1399,7 +1407,8 @@ the `advanced.excludedEnvVars` setting in your `settings.json` file.
 - **`GOOGLE_CLOUD_LOCATION`**:
   - Your Google Cloud Project Location (e.g., us-central1).
   - Required for using Vertex AI in non-express mode.
-  - Example: `export GOOGLE_CLOUD_LOCATION="YOUR_PROJECT_LOCATION"`.
+  - Example: `export GOOGLE_CLOUD_LOCATION="YOUR_PROJECT_LOCATION"` (Windows
+    PowerShell: `$env:GOOGLE_CLOUD_LOCATION="YOUR_PROJECT_LOCATION"`).
 - **`GEMINI_SANDBOX`**:
   - Alternative to the `sandbox` setting in `settings.json`.
   - Accepts `true`, `false`, `docker`, `podman`, or a custom command string.

docs/reference/policy-engine.md

@@ -10,9 +10,19 @@ confirmation.
 To create your first policy:
 
 1.  **Create the policy directory** if it doesn't exist:
+
+    **macOS/Linux**
+
     ```bash
     mkdir -p ~/.gemini/policies
     ```
+
+    **Windows (PowerShell)**
+
+    ```powershell
+    New-Item -ItemType Directory -Force -Path "$env:USERPROFILE\.gemini\policies"
+    ```
+
 2.  **Create a new policy file** (e.g., `~/.gemini/policies/my-rules.toml`). You
     can use any filename ending in `.toml`; all such files in this directory
     will be loaded and combined: