Change longterm line chart to bar chart

[absternator]

After discussions with jack. we have decided to change the long term cases chart to be a grouped bar chart. This was because the line chart was a bit confusing to interpret. The new bar chart allows us to more easily interpret how cases change with updating baseline parameters and interventions.

Testing:
Can use mint-dev as its deployed on there. Just run a region and then go to long term. play around with changing formvalues.

OLD

## NEW

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.40%. Comparing base (c6a6c49) to head (54e8fb4).
⚠️ Report is 18 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #49      +/-   ##
==========================================
- Coverage   91.55%   91.40%   -0.15%     
==========================================
  Files          78       78              
  Lines        1574     1535      -39     
  Branches      288      282       -6     
==========================================
- Hits         1441     1403      -38     
+ Misses        117      116       -1     
  Partials       16       16              

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[Copilot]

Pull request overview

Updates the region “Compare” long-term cases visualization from a line chart to a grouped column (bar) chart, aiming to make differences between present/baseline-long-term/full-long-term scenarios easier to interpret.

Changes:

• Switched compare chart series and Highcharts config from line to column, including category x-axis + cost shown via data labels.
• Updated the compare results component to pass scenario ordering into getCasesCompareConfig.
• Updated (and removed now-obsolete parts of) the cases chart config unit tests to reflect the new chart type/signature.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
client/src/lib/charts/casesConfig.ts	Reworks compare chart config to a column chart with category x-axis and cost data labels.
client/src/routes/projects/[project]/regions/[region]/compare/_components/CompareResults.svelte	Passes derived scenario list into the updated compare chart config function.
client/src/routes/projects/[project]/regions/[region]/compare/+page.server.ts	Adds explicit typing for compareParameters.
client/src/tests/lib/charts/casesConfig.spec.ts	Updates tests for new column-series behavior and new getCasesCompareConfig signature; removes tests for removed helpers.

[Copilot]

createCasesCompareSeries builds data via Object.entries(totalCasesAndCosts), but the chart’s x-axis categories come from the separate scenarios array in getCasesCompareConfig. If any series is missing a scenario (or objects have different key insertion order), points will be plotted under the wrong category index, breaking the grouped-bar comparison and shared tooltip.

To fix, build each series’ data by mapping over the scenarios array (and inserting null/undefined y values for missing scenarios), or explicitly set x based on the scenario index so all series align with xAxis.categories.

[Copilot]

This spec uses vi.spyOn(...) later in the file but vi is no longer imported from vitest, so the tests will fail at runtime. Add vi back to the Vitest import (or avoid vi in the test).

Suggested change

	import { describe, expect, it } from 'vitest';
	import { describe, expect, it, vi } from 'vitest';