feat: add admin user management and in-app system guide

[douzhenyu]

What type of PR is this?

• API-change
• BUG
• Improvement
• Documentation
• Feature
• Test and CI
• Code Refactoring

Which issue(s) this PR fixes:

N/A

What this PR does / why we need it:

This PR adds role-based authentication and an in-app system guide so accounts can be centrally managed and users can quickly learn and try the system.

Administrator and user management

• Adds administrator and regular-user roles and disables public registration.
• Synchronizes one fixed administrator account at startup. The default credentials are:
  • Username: admin
  • Password: User@123
• Supports overriding the administrator credentials with ADMIN_USERNAME and ADMIN_PASSWORD. Production deployments should replace the default password.
• Adds administrator-only user management APIs and UI for creating users, enabling/disabling accounts, setting expiration dates, maintaining remarks, and resetting passwords.
• Prevents regular users from viewing or calling user-management features while retaining access to existing business functionality.
• Revalidates account status on authenticated requests and invalidates existing sessions after disablement, expiration, or password reset.
• Improves the shared login experience with password visibility, loading/error states, and centralized-account guidance.

System guide and sample files

• Adds a bilingual Chinese/English system guide covering feature overview, operating steps, administrator operations, sample data, and FAQs.
• Opens the guide as a right-side drawer within the application, consistent with Data Table Management and Knowledge Base interactions.
• Adds two fictional sample datasets that can be imported directly through Data Table Management:
  • CSV runtime URL: /samples/hk-stock-daily-sample.csv
  • CSV repository link: https://github.com/matrixorigin/hk-sfc-poc/blob/feature/system-guide-samples/web/public/samples/hk-stock-daily-sample.csv
  • XLSX runtime URL: /samples/hk-company-financials-sample.xlsx
  • XLSX repository link: https://github.com/matrixorigin/hk-sfc-poc/blob/feature/system-guide-samples/web/public/samples/hk-company-financials-sample.xlsx
• Keeps the existing PDF manual for compatibility with historical direct links.

Validation

• go test ./... passed.
• npm run build passed.
• Targeted ESLint checks for the new authentication, guide, user-management, and API files passed.
• The repository-wide npm run lint still reports 53 errors and 4 warnings in pre-existing files outside this PR's new feature scope.