[pull] main from supermemoryai:main - #458

…locked' (#1406)

## Why?

Plain **T-1554**: a user with a **read-only** MCP OAuth grant got 403s on memory listing, and the client rendered them as *"Access forbidden. Your account may be restricted or blocked."* The API's actual error body said `{"error": "This API key has read-only access"}` — but `handleError` discarded it, so the user (and support) chased a nonexistent account ban.

Two masking layers:
1. `handleError` used the raw error `message`, which for our raw-fetch endpoints was a hardcoded string ("Failed to fetch documents") or unparsed JSON, and fell back to the scary "restricted or blocked" text when empty.
2. `getDocuments` didn't read the response body at all.

## What?

- New `extractApiErrorMessage()` unwraps JSON error bodies (`{"error": ...}` / `{"message": ...}`) so the API's real reason reaches the user.
- `getDocuments` and `listMemoryEntries` now pass the (unwrapped) response body through with the status, letting `handleError` apply status-aware fallbacks when the body is empty.
- Reworded the empty-body 403 fallback to point at the common cause first: *"Access forbidden. This connection may be read-only or scoped to specific spaces — reconnect with broader access, or check your account status."*

Companion API-side fix (read-only grants couldn't call semantically-read POST list endpoints at all): supermemoryai/mono#2772.

## Testing

- Added tests: a 403 with a JSON error body surfaces the API's message; an empty-body 403 gets the scope-aware fallback. `vitest run src/server/client/index.test.ts` — 3 passed.
- `tsc --noEmit -p tsconfig.json` clean. (The `check-types` script also runs `tsconfig.widget.json`, which fails on origin/main with a pre-existing `UseAppOptions.strict` error, unrelated.)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> **Low Risk**
> User-facing error text only in the MCP client; no auth or API behavior changes.
>
> **Overview**
> **MCP client errors now show what the API actually returned** instead of hardcoded strings or misleading “restricted or blocked” text.
>
> Adds `extractApiErrorMessage()` to parse JSON bodies (`error` / `message` fields) from failed responses. **`getDocuments`** and **`listMemoryEntries`** read the response body on non-OK status and attach the unwrapped message (with status) for **`handleError`**, which also uses the helper on error messages. When a 403 has no body message, the fallback now points users toward **read-only or scoped OAuth** rather than an account ban.
>
> <sup>Reviewed by [Cursor Bugbot](https://cursor.com/bugbot) for commit 1f49247. Bugbot is set up for automated code reviews on this repo. Configure [here](https://www.cursor.com/dashboard/bugbot).</sup>
<!-- /CURSOR_SUMMARY -->