[cyphalle]

Review the Rust of statusline() and the new unit helpers.

The status line becomes:

⚡ 1.4 kWh · 💧 7.6 L · 410.7 gCO₂e ≈ 🚗 1.7 km · 🌱 0.08–0.13 PDF·m²·yr ≈ 1.7 A4 sheets

Methodo & data decisions

• PDF·m²·yr = species·yr / 1.48e-8 species per m². The report already shows this value as "m² of land". Alternative: species·yr. It reads 1e-9 per session and means nothing to a reader.
• The range runs over the candidate sites, like the report. Alternative: one mean value. That adds an equal-split assumption that the tool does not make elsewhere.
• Car: EPA, 400 g CO₂ per mile (248.5 g/km). Alternative: ADEME. The data centres are in the US.
• Area: the largest reference area (A4, parking space, tennis court, football pitch, hectare) that the middle of the range fills once. One value only, because this is an order of magnitude.

Sources in METHODOLOGY.md. Tests: 11 green, clippy clean.

🤖 Generated with Claude Code

https://claude.ai/code/session_01QUg7CcESDGqbwXB484UeRx