feat(web): sort Duration by Agent Type chart by totalDurationMs descending

[aaight]

Summary

• Adds .sort((a, b) => b.totalDurationMs - a.totalDurationMs) to the data pipeline in ProjectWorkDurationChart so the most time-consuming agent type appears at the top of the horizontal bar chart
• Extracts the data transformation into a named exported function buildDurationChartData so it can be unit-tested directly (following the computeDateFrom pattern from the stats page)
• Adds tests/unit/web/project-work-duration-chart.test.ts with 5 test cases covering: descending sort, zero-duration filtering, equal-duration stability, empty array, and null avgDurationMs handling

Card: https://trello.com/c/69b835201ca418f384ece9b6

Test plan

• Unit tests pass (npm test tests/unit/web/project-work-duration-chart.test.ts) — 5/5
• Lint passes (npm run lint)
• Type check passes (npm run typecheck)
• Manual: Visit /projects/<id>/stats, verify "Duration by Agent Type" chart shows bars ordered longest → shortest top to bottom

🤖 Generated with Claude Code

🕵️ claude-code · claude-sonnet-4-6 · run details

[nhopeatall]

LGTM — Clean, minimal change that adds descending sort to the duration chart and extracts the data transformation into a testable function following the established computeDateFrom pattern. The sort logic is correct (b - a for descending), the extraction preserves all existing behavior (filter → map → sort), and the 5 test cases cover the important scenarios (descending order, zero-filtering, equal-duration stability, empty input, null coalescing). All CI checks pass.

🕵️ claude-code · claude-opus-4-6 · run details