Add estimated water usage tracking to token usage display

[Copilot]

• Add water usage estimation constants and interface updates
• Implement water usage calculation in calculateDetailedStats method
• Add water usage display to status bar tooltip
• Add water usage display to detailed HTML panel
• Add calculation explanation for water usage estimation
• Test the implementation and verify all displays work correctly
• Remove package-lock.json from changeset per review feedback

✅ Implementation Complete

Water Usage Estimation Feature Successfully Added

Key Features Implemented:

• Estimation Rate: 0.3 liters per 1000 tokens (based on data center water usage research)
• Status Bar Tooltip: Shows "Water Est.: X.XXXL" for both today and monthly usage
• Detailed Panel: New table row with 💧 icon showing water usage across time periods
• Projection: Includes yearly projection based on current month usage
• Documentation: Added calculation explanation describing data center water usage

Technical Implementation:

• Updated DetailedStats interface with waterUsage: number field
• Added waterUsagePer1kTokens = 0.3 constant
• Integrated water calculation alongside existing CO₂ calculations
• Updated HTML generation with proper formatting (3 decimal places)
• All code compiles successfully with no lint errors
• Removed unnecessary package-lock.json changes per review feedback

UI Integration:

• Tooltip displays water usage below CO₂ estimates
• Detail panel shows water row between CO₂ and tree equivalent rows
• Consistent styling and formatting with existing metrics
• Clear explanation in "Calculation & Estimates" section

The feature provides users with insight into their environmental impact beyond just CO₂, helping them understand the water resources consumed by their AI usage.

Original prompt

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This section details on the original issue you should resolve

<issue_title>Show the estimated water usage</issue_title>
<issue_description>show in the flyout and the detail panel the estimated liters of water used with the tokens.

Also add the info how that calculation is done</issue_description>

Comments on the Issue (you are @copilot in this section)

Fixes #10

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[rajbos]

@copilot remove the package.json from this changeset, that change is not needed

[Copilot]

@copilot remove the package.json from this changeset, that change is not needed

Removed package-lock.json from the changeset. The file has been reverted to its original state before my changes, keeping only the water usage feature implementation in src/extension.ts.