feat: polish rod and trajectory UX interactions

Improve Majic Rod Solver usability with denser table controls, clearer unit-aware guidance, and stronger accessibility affordances for keyboard/screen-reader workflows.

Made-with: Cursor

gui-ts/src/ui/tabs/PumpTab.tsx

@@ -14,6 +14,7 @@ type Props = { store: CaseStore };
 
 export function PumpTab({ store }: Props) {
   const { state, update } = store;
+  const isMetric = state.unitsSelection === 1;
 
   const pumpOptions = useMemo(() => {
     const mmVals = PUMP_PLUNGER_INCH_OPTIONS.map((inchVal) => pumpDiameterMmFromInches(inchVal));
@@ -37,7 +38,11 @@ export function PumpTab({ store }: Props) {
         <Row
           label="Plunger diameter"
           htmlFor="plungerDiam"
-          hint="Stored as mm in the case file when above 2 (same convention as rod OD)."
+          hint={
+            isMetric
+              ? "Metric-first display with imperial equivalent in each option."
+              : "Imperial-first display with metric equivalent in each option."
+          }
         >
           <SelectField
             id="plungerDiam"
@@ -47,7 +52,11 @@ export function PumpTab({ store }: Props) {
             ariaLabel="Pump plunger diameter"
           />
         </Row>
-        <Row label="Pump Friction" htmlFor="pumpFric" hint="lbf (imperial)">
+        <Row
+          label="Pump Friction"
+          htmlFor="pumpFric"
+          hint={isMetric ? "N (SI case)" : "lbf (imperial oilfield case)"}
+        >
           <NumberField
             id="pumpFric"
             value={state.pumpFriction}
@@ -55,7 +64,11 @@ export function PumpTab({ store }: Props) {
             onChange={(v) => update("pumpFriction", v)}
           />
         </Row>
-        <Row label="Pump Intake Pressure" htmlFor="pumpIntake" hint="psi (imperial)">
+        <Row
+          label="Pump Intake Pressure"
+          htmlFor="pumpIntake"
+          hint={isMetric ? "Pa (SI case)" : "psi (imperial oilfield case)"}
+        >
           <NumberField
             id="pumpIntake"
             value={state.pumpIntakePressure}