Add safe local development seed data

[LoopyB]

Summary

Adds a deterministic, local-only seed-data workflow for SecureShift development.

This gives backend, frontend and Guard App developers a populated local database without requiring everyone to manually create users, branches, shifts and related records.

Seeded data

• 6 roles
• 7 fictional users
• 2 branches
• 4 availability records
• 5 shift scenarios
• 1 attendance record
• 1 payroll record
• 2 messages
• 3 notifications

The seed includes admin, employer and guard personas covering approved, pending and rejected/expired scenarios.

Commands

npm run seed
npm run seed:reset

Reset requires:

SEED_ALLOW_LOCAL=true
SEED_RESET_CONFIRM=SecureShiftLocalReset

Safety

The seed refuses to run unless all safety checks pass:

• NODE_ENV is not production
• MONGO_URI is explicitly set
• only secureshift_local, secureshift_dev or secureshift_test are allowed
• Atlas/SRV and remote hosts are rejected
• reset removes only deterministic seeded records
• missing MONGO_URI cannot fall back to Atlas

Payroll isolation

Seed payroll generation is scoped only to deterministic seeded shift IDs.

It does not absorb unrelated developer-created shifts, and reset preserves unrelated local records.

Validation

• 19 safety tests passed
• 1 payroll isolation test passed
• focused ESLint passed
• git diff --check passed
• running the seed twice produced identical counts
• reset removed all seeded records
• unrelated shift and notification records were preserved

Notes

• No Guard App or employer frontend files were changed
• No OTP bypass was added
• No attendance or emergency-controller behaviour was changed
• Local test password: SecureShift1!