[codex] simplify TokChat user roles

[yaojingang]

Summary

• Simplify TokChat user-management role options to 普通用户 and 系统管理员.
• Change the default frontend user role from sales_rep to user.
• Normalize legacy sales_rep and sales_manager rows to user during database initialization.
• Keep existing admin user-role records displayed as 系统管理员.
• Add backend role validation/normalization for create, update, and list filters.

Validation

• php -l tools/tokchat/admin.php
• php -l tools/tokchat/api/users.php
• php -l tools/tokchat/api/db.php
• temporary SQLite check: seeded users use user; legacy sales_manager is migrated to user
• git diff --check

[augmentcode]

🤖 Augment PR Summary

Summary: This PR simplifies TokChat’s user-role model to just user (普通用户) and admin (系统管理员).

Changes:

• Updates the admin UI to only offer the two roles and sets the default user role to user.
• Normalizes legacy sales_rep/sales_manager rows to user during DB initialization and updates demo seed data accordingly.
• Adds backend role normalization/validation for user list filters and for create/update requests.

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[augmentcode]

Review completed. 1 suggestion posted.

Comment augment review to trigger a new review at any time.

[augmentcode]

normalizeLegacyUserRoles($db) is executed without a try/catch, so initDatabase() will fail hard if an existing users table predates the role column (or otherwise lacks it). Consider guarding this update similarly to the other migration-style ALTER TABLE blocks so upgrades don’t break on older/corrupt schemas.

Severity: medium

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