Key Assumptions and Clarifications

The source requirements are strong, but several operational rules must be made explicit for implementation.

3.1 Non-destructive records

The following records are never physically deleted:

• Person
• Collaborator
• Current Account Entry
• Mine Well Production
• Gold Price
• Price List Items
• Reference Data

Instead, records are managed with status flags, activity flags, effective dates, or reversal records.

3.2 Modular monolith first

The recommended architecture is a modular monolith, not microservices, because:

• business rules are tightly coupled,
• SQLite is the requested database,
• deployment simplicity matters for remote operations,
• transaction safety across accounting workflows is easier in one process,
• future extraction to services remains possible.

3.3 Ledger is the source of truth

Balances are derived from immutable current-account entries and reversals, not from mutable balance fields.

3.4 Dual-currency ledger

The system tracks accounting in two units:

• BRL (Real)
• Gold grams

A current-account entry belongs to exactly one currency. Summaries compute balances separately for each currency.

3.5 Salary accrual cadence

Because salary is specified as a monthly salary, but work planning operates in daily work periods, the design assumes:

• monthly salary is normalized to a daily accrual rate for daily projected earning calculations,
• the normalization formula is configurable,
• the default formula is monthly_salary / 30.

3.6 Daily period model

Mine-well production is recorded by:

• date
• period
• well

Each period is a 12-hour shift. The plan/accrual engine uses a formal work_period entity to anchor planning and earnings.

3.7 Commission basis

Commissioned collaborators earn based on:

• assigned work well,
• work period,
• recorded well production,
• collaborator commission percentage.

If required production is missing, accrual status remains pending until production is recorded.

3.8 Sick-day and license rules

The specification implies substitution-based earnings transfer logic. The implementation will support explicit substitution links so every exception is auditable.

3.9 Work journey lifecycle

A collaborator journey has:

• start date,
• default end date = start date + 90 days,
• extension days,
• projected end date = default end + extension days,
• status transitions,
• closure workflow.

3.10 Role model

Initial recommended roles:

• Administrator: full access
• Planner: planning, accrual, production support
• Mercantile Operator: expense entry, read summaries
• Finance Viewer: read-only reports and ledgers