docs: add generated-output README and legacy-guide pointer

Author: pomfrida

documentation/how-to/TOKEN_SYSTEM_GUIDE.md

@@ -1,5 +1,10 @@
 # Token System Guide
 
+> **Note:** A new Tokens Studio-based pipeline is being phased in — see
+> [`documentation/agent-instructions/TOKENS_STUDIO.md`](../agent-instructions/TOKENS_STUDIO.md).
+> This guide covers the **legacy pipeline** (Figma REST sync + Style Dictionary),
+> which still owns everything the `@equinor/eds-tokens` package publishes.
+
 This guide provides a comprehensive walkthrough of the <abbr title="Equinor Design System">EDS</abbr> token system – from Figma setup through syncing, building, and implementation. It covers the complete token lifecycle and serves as documentation for working with design tokens in the EDS.
 
 ## Table of Contents

packages/eds-tokens/src/tokens/README.md

@@ -0,0 +1,19 @@
+# Generated token output — do not edit
+
+Everything in this directory is written by the Tokens Studio release
+workflow (`.github/workflows/tokens_studio_release.yaml`) and committed
+through its automated pull requests. **Never edit these files by hand** —
+the next release run regenerates them and silently overwrites manual
+changes. Fix token values in Tokens Studio instead.
+
+| Directory  | Content                                | Produced by                                     |
+| ---------- | -------------------------------------- | ----------------------------------------------- |
+| `<alias>/` | Raw token sets (JSON, with `{alias}`s) | `studio tokens pull` (sources in `.studio.json`) |
+| `css/`     | CSS custom properties                  | `studio exports run` (EDS-CSS configuration)    |
+| `dtcg/`    | DTCG interchange JSON                  | `studio exports run` (EDS-DTCG configuration)   |
+| `ts/`      | TypeScript modules                     | `pnpm run generate:ts-tokens` (combines `dtcg/` + `css/`) |
+
+None of this is wired into the package `exports` map yet — the published
+artifacts still come from the legacy Style Dictionary build in `build/`.
+
+Pipeline documentation: [`documentation/agent-instructions/TOKENS_STUDIO.md`](../../../../documentation/agent-instructions/TOKENS_STUDIO.md).