Edit Issue - .issue.db

Title *

Description

Implement DELETE /api/v1/admin/users/<user_id> endpoint to delete or deactivate users.

**API Specification:**
- Endpoint: DELETE /api/v1/admin/users/<user_id>
- Permission Required: manage_users
- Path Parameter: user_id (UUID)
- Query Parameter: hard_delete (bool, default: false)
- Response: {success: true, action: 'deactivated' | 'deleted'}

**Soft Delete (default):**
- Set is_active = false
- Revoke all active tokens
- Terminate all sessions
- Keep user data for audit trail
- User cannot login but data preserved

**Hard Delete (hard_delete=true):**
- Only allowed for users with no workflow history
- Permanently remove user record
- Remove from all role assignments
- Anonymize audit logs (replace email with 'deleted_user_<uuid>')

**Requirements:**
- Cannot delete yourself
- Cannot delete last tenant_admin
- Warn if user has active workflows
- Log audit event

**IMPORTANT:** Implement with ultra attention to details and correctness.
**BEFORE CLOSING:** Take screenshot showing user deletion. Add comment summarizing implementation.

Due Date (YYYY-MM-DD)

Tags (comma separated)

Related Issues (IDs)

Enter IDs of issues related to this one. They will be linked as 'related'.

Edit Issue #41