The intraday chart data builder lived inside dashboard-utils with observation-source and TAF helpers, so chart consumers had to depend on the large dashboard utility surface. This moves chart data preparation, observation-source helpers, and TAF marker labels into focused modules while keeping dashboard-utils re-export compatibility.
Constraint: Preserve existing chart data shape, observation labels, TAF labels, and legacy dashboard-utils exports.
Rejected: Rewrite chart data generation while moving it | this pass is a boundary move only so visual behavior remains stable.
Confidence: high
Scope-risk: moderate
Reversibility: clean
Tested: TypeScript diagnostics for chart-utils, dashboard-utils, observation-source-utils, and taf-utils
Tested: npm run build
Not-tested: Browser visual regression across every chart city.
AmandaloveYang