fix: respect percentDisplayMode in /quota command

[XDayonline]

Summary

The /quota slash command hardcodes % left regardless of the percentDisplayMode config setting. This makes it inconsistent with the sidebar and compact status, which correctly respect the setting.

Problem

1. Set percentDisplayMode: "used" in config
2. Sidebar shows XX% used (correct)
3. /quota shows XX% left (wrong — ignores config)

Root Cause

src/lib/quota-command-format.ts:75 hardcodes:

lines.push(`  ${labelCol} ${bar(pct, barWidth)}  ${pct}% left${suffix}`);

While sidebar/compact use formatDisplayedPercentLabel() which respects percentDisplayMode.

Fix

• Import formatDisplayedPercentLabel in quota-command-format.ts
• Replace hardcoded % left with formatDisplayedPercentLabel(row.percentRemaining, params.percentDisplayMode)
• Pass percentDisplayMode from runtime.config through handleQuotaSlashCommand
• Update test to verify new behavior

Testing

• All 26 tests in tests/plugin.quota-command.test.ts pass
• TypeScript typecheck passes

Closes #116