ANL-03: Forecasting and capacity-planning service (heuristic-first)

[Chris0Jeky]

Source:

• docs/WIP/FutureExpansionAndImprovementsChecklist.pdf (2.5 Forecasting & Capacity Planning)

Horizon:

• Future expansion tranche (post current Phase 4 backlog)

Depends on:

• ARCH-01: Multi-tenancy strategy ADR and tenant-isolation readiness checklist #71
• DEBT-02: Log query scalability pass #53

Scope:

• Introduce heuristic forecasting model using historical throughput/cycle-time inputs.
• Provide confidence-banded completion estimates and capacity guidance suggestions.
• Keep initial model deterministic and explainable before any ML-style expansion.

Acceptance Criteria:

• Forecast endpoint provides explainable inputs/outputs with documented assumptions.
• UI displays estimate ranges and confidence caveats clearly.
• Tests cover edge cases (sparse history, outliers, zero-throughput windows).
• Forecast computation performance budget is defined and validated.

Suggested branch:

• feature/forecasting-capacity-heuristics