docs: document VS Code local telemetry (#26215)

Document local telemetry behavior, diagnostics commands, support bundle contents, and the VS Code telemetry event reference.

docs/support/support-bundle.md

@@ -53,6 +53,7 @@ A brief overview of all files contained in the bundle is provided below:
 | `workspace/template.json`         | The template currently in use by the selected workspace.                                                                          |
 | `workspace/template_file.zip`     | The source code of the template currently in use by the selected workspace.                                                       |
 | `workspace/template_version.json` | The template version currently in use by the selected workspace.                                                                  |
+| `vscode-logs/`                    | Only present when generated from the VS Code Coder Remote extension. Includes logs, redacted settings, and local telemetry files. |
 
 ## How do I generate a Support Bundle?
 
@@ -76,6 +77,13 @@ A brief overview of all files contained in the bundle is provided below:
    prompt. The support bundle will be generated in the current directory with
    the filename `coder-support-$TIMESTAMP.zip`.
 
+   If you use VS Code, you can also run **Coder: Create Support Bundle** from
+   the Command Palette. The VS Code Coder Remote extension runs
+   `coder support bundle` and appends recent VS Code diagnostics to the
+   generated archive. Bundles created with the CLI alone do not include
+   `vscode-logs/`. Learn more about
+   [VS Code diagnostics](../user-guides/workspace-access/vscode.md#diagnostics-and-support-bundles).
+
    > [!NOTE]
    > While support bundles can be generated without a running workspace, it is
    > recommended to specify one to maximize troubleshooting information.

docs/user-guides/workspace-access/vscode.md

@@ -34,6 +34,73 @@ ext install coder.coder-remote
 Alternatively, manually install the VSIX from the
 [latest release](https://github.com/coder/vscode-coder/releases/latest).
 
+## Local telemetry
+
+The Coder Remote extension records local telemetry to help diagnose extension
+and workspace connection issues. Telemetry is stored on your machine. It is not
+sent to Coder unless you export it or include it in a support bundle and share
+that file.
+
+Local telemetry is controlled by the VS Code setting `coder.telemetry.level`:
+
+| Value   | Behavior                                                      |
+|---------|---------------------------------------------------------------|
+| `off`   | Disable extension telemetry collection.                       |
+| `local` | Record telemetry events on this machine. This is the default. |
+
+### Stored data
+
+Telemetry can include diagnostic details such as extension version, VS Code
+version, operating system, machine and session identifiers, deployment URL,
+workspace and agent names, command outcomes, connection state, request routes,
+timing, and error details. It does not intentionally collect source code,
+terminal contents, tokens, or credentials.
+
+### Tracked activity
+
+The exact events vary by extension version. For a comprehensive list of current
+events, properties, and attributes, see the
+[extension event reference](https://github.com/coder/vscode-coder/blob/main/src/instrumentation/EVENTS.md).
+The following categories summarize the diagnostic signals the extension may
+record:
+
+| Area                           | Examples                                                                                     |
+|--------------------------------|----------------------------------------------------------------------------------------------|
+| Extension lifecycle            | Activation, deployment initialization, and configuration loading.                            |
+| Authentication and credentials | Sign-in state, token refresh, logout, credential storage, and deployment recovery.           |
+| Commands and diagnostics       | Command outcomes, telemetry exports, support bundle creation, ping, and speed tests.         |
+| Workspace workflows            | Workspace selection, open attempts, dev container handoff, start, and update prompts.        |
+| CLI and remote setup           | CLI binary resolution, download, verification, configuration, and setup through SSH handoff. |
+| Connection health              | Workspace and agent state transitions, reconnects, SSH process health, and network samples.  |
+| HTTP diagnostics               | Normalized routes, status classes, and latency rollups.                                      |
+
+### Storage and retention
+
+The extension stores telemetry as JSON Lines files in its VS Code global storage
+under a `telemetry` directory. Files rotate at 5 MiB, are kept for up to 30 days,
+and are capped at 100 MiB total by default.
+
+You can tune local retention with the advanced `coder.telemetry.local` setting.
+Most users should keep the default values.
+
+### Diagnostics and support bundles
+
+The extension includes commands for collecting diagnostics from VS Code:
+
+- **Coder: Export Telemetry** exports only local telemetry. Choose a date range
+  and JSON or OTLP JSON zip format, then review the file before sharing it.
+- **Coder: Create Support Bundle** runs `coder support bundle` and adds a
+  `vscode-logs/` directory with recent VS Code extension diagnostics, including
+  extension logs, proxy and Remote-SSH logs, redacted VS Code settings, and
+  local telemetry files when available. The `vscode-logs/` directory is only
+  added when the bundle is created from the VS Code Coder Remote extension;
+  bundles created with the CLI alone do not include it.
+- **Coder: View Logs** opens the extension output logs in VS Code.
+
+Support bundles can contain sensitive diagnostic data. Review the generated
+bundle before sharing it. Learn more about
+[support bundles](../../support/support-bundle.md).
+
 ## VS Code extensions
 
 There are multiple ways to add extensions to VS Code Desktop: