Linked Issue

Closes #5969

Description

TypeScript CLI counterpart of #5936 (Python). deleteEntities() walks every entity it's asked to delete, but writes each API response into one result variable that gets overwritten on the next pass, so only the last entity's response makes it back:

let result: Record<string, unknown> = {};
for (const [entityType, entityId] of entities) {
    result = (await this._request("DELETE", `/v2/entities/${entityType}/${entityId}/`, ...));
}
return result;

mem0 entity delete accepts --user-id, --agent-id, --app-id, and --run-id together, and the entities command prints this value via formatJson(result) under --output json. Delete two entities and the JSON only shows one.

The fix collects each response into a record keyed by entity type ({ user: {...}, agent: {...} }), matching the Python fix. Nothing is dropped, the deletes always happened (one request each), and the Promise<Record<string, unknown>> return type is unchanged.

Type of Change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Refactor (no functional changes)
• Documentation update

Breaking Changes

The JSON shape of mem0 entity delete --output json changes from a single raw API response to a map keyed by entity type, only in the multi-entity case (which was lossy before). Human and agent output modes are unaffected. Kept consistent with the Python fix in #5936.

Test Coverage

• I added/updated unit tests
• I added/updated integration tests
• I tested manually (describe below)
• No tests needed

Added tests/platform-backend.test.ts covering multi-entity (fails without the fix), single-entity, and the no-entity error. _request is spied, so no network calls. Full vitest suite passes and tsc --noEmit is clean.

Checklist

• My code follows the project's style guidelines
• I have performed a self-review of my code
• I have added tests that prove my fix works
• New and existing tests pass locally
• I have updated documentation if needed (no user-facing docs affected)