[QI83]

Summary

Adds a configurable long window for the OpenCode provider. The OpenCode widget row currently shows the 5-hour session plus a single long window chosen automatically (whichever of the 7-day and 30-day windows is more constrained). This change lets the user pick which long window appears, through a new Long period dropdown in Settings → Providers → OpenCode with two options: Weekly (7d) and Monthly (30d), defaulting to Monthly.

Motivation

The auto-selection effectively hid the weekly window whenever the monthly window was larger, so users could not see their weekly usage at a glance.

Changes

• UsageData gains a weekly_7d field carrying the raw 7-day window (the existing weekly field keeps its auto-selected value for other consumers).
• New OpenCodeLongWindow { Weekly, Monthly } setting (default Monthly), exposed as a dropdown in the OpenCode settings.
• Theme bindings: {opencode}.weekly_7d.* and {opencode}.long_window ("weekly" / "monthly").
• The three bundled themes render the chosen long window (7d or 30d) as the second OpenCode row.
• i18n: new Long period label plus Collect usage from OpenCode Go / Collect usage from Cursor descriptions across all 14 locales.

Testing

• cargo build clean.
• cargo test --bin claude-code-usage-monitor: 605 passed, 0 failed.
• Manually verified the widget renders the selected window (weekly/monthly) in all three bundled themes.

Checklist

• Tests pass
• No changes to unrelated providers
• All 14 locale files stay in key parity