feat(docs): add +revisions helper to list document revision history

.changeset/docs-revisions-helper.md

@@ -0,0 +1,5 @@
+---
+"@googleworkspace/cli": minor
+---
+
+Add `gws docs +revisions` helper to list revision history for a Google Docs document

skills/gws-docs-revisions/SKILL.md

@@ -0,0 +1,72 @@
+---
+name: gws-docs-revisions
+version: 1.0.0
+description: "Google Docs: List revision history for a document."
+metadata:
+  openclaw:
+    category: "productivity"
+    requires:
+      bins: ["gws"]
+    cliHelp: "gws docs +revisions --help"
+---
+
+# docs +revisions
+
+> **PREREQUISITE:** Read `../gws-shared/SKILL.md` for auth, global flags, and security rules. If missing, run `gws generate-skills` to create it.
+
+List revision history for a Google Docs document.
+
+## Usage
+
+```bash
+gws docs +revisions --document <ID> [--limit <N>]
+```
+
+## Flags
+
+| Flag | Required | Default | Description |
+|------|----------|---------|-------------|
+| `--document` | ✓ | — | Document ID (from the URL) |
+| `--limit` | — | 20 | Maximum number of revisions to return (1–1000) |
+
+## Examples
+
+```bash
+# Show last 20 revisions (default)
+gws docs +revisions --document 1BxiMVs0XRA5nFMdKvBdBZjgmUUqptlbs74OgVE2upms
+
+# Show last 5 revisions
+gws docs +revisions --document 1BxiMVs0XRA5nFMdKvBdBZjgmUUqptlbs74OgVE2upms --limit 5
+```
+
+## Output
+
+Each revision includes:
+
+| Field | Description |
+|-------|-------------|
+| `id` | Revision ID |
+| `modifiedTime` | When this revision was created |
+| `lastModifyingUser.displayName` | Who made the change |
+| `keepForever` | Whether this revision is pinned (won't be auto-deleted) |
+| `size` | Size of the revision in bytes |
+
+## Limitations
+
+> [!IMPORTANT]
+> **Content is not available.** The Google Drive API returns revision *metadata* only for
+> native Google Docs files. The actual text content of past revisions cannot be retrieved
+> via API — only the current content is accessible via `gws docs documents get`.
+>
+> To read a specific revision's content, open the document in Google Docs and use
+> **File → Version history → See version history**.
+
+## Scope
+
+This command uses the `drive.readonly` OAuth scope. No write access is required.
+
+## See Also
+
+- [gws-shared](../gws-shared/SKILL.md) — Global flags and auth
+- [gws-docs](../gws-docs/SKILL.md) — All Google Docs commands
+- [gws-docs-write](../gws-docs-write/SKILL.md) — Append text to a document

skills/gws-docs/SKILL.md

@@ -23,6 +23,7 @@ gws docs <resource> <method> [flags]
 | Command | Description |
 |---------|-------------|
 | [`+write`](../gws-docs-write/SKILL.md) | Append text to a document |
+| [`+revisions`](../gws-docs-revisions/SKILL.md) | List revision history for a document |
 
 ## API Resources
 

src/error.rs

@@ -96,6 +96,50 @@ impl GwsError {
         }
     }
 
+    /// Build a [`GwsError::Api`] by parsing a Google API error response body.
+    ///
+    /// Extracts `code`, `message`, `reason`, and (for `accessNotConfigured` errors) the
+    /// GCP console URL to enable the API. Falls back to the raw body when the
+    /// response is not well-formed Google JSON.
+    pub fn from_api_response(status: u16, body: &str) -> Self {
+        let err_json: Option<serde_json::Value> = serde_json::from_str(body).ok();
+        let err_obj = err_json.as_ref().and_then(|v| v.get("error"));
+        let code = err_obj
+            .and_then(|e| e.get("code"))
+            .and_then(|c| c.as_u64())
+            .map(|c| c as u16)
+            .unwrap_or(status);
+        let message = err_obj
+            .and_then(|e| e.get("message"))
+            .and_then(|m| m.as_str())
+            .unwrap_or(body)
+            .to_string();
+        let reason = err_obj
+            .and_then(|e| e.get("errors"))
+            .and_then(|e| e.as_array())
+            .and_then(|arr| arr.first())
+            .and_then(|e| e.get("reason"))
+            .and_then(|r| r.as_str())
+            .or_else(|| {
+                err_obj
+                    .and_then(|e| e.get("reason"))
+                    .and_then(|r| r.as_str())
+            })
+            .unwrap_or("unknown")
+            .to_string();
+        let enable_url = if reason == "accessNotConfigured" {
+            crate::executor::extract_enable_url(&message)
+        } else {
+            None
+        };
+        GwsError::Api {
+            code,
+            message,
+            reason,
+            enable_url,
+        }
+    }
+
     pub fn to_json(&self) -> serde_json::Value {
         match self {
             GwsError::Api {