feat(ui): circular match-score ring in job workspace

Second UI-rework pass. The job workspace mockup's signature element is
a donut "coverage" ring for the deterministic CV match score; the app
had a linear progress bar instead. Replaced with a layered
CircularProgress ring (track + value arc, percentage centered) while
keeping every existing feature (band chip, matched/missing keyword
chips, section coverage) -- this is a pure visual upgrade to the
existing MatchScoreCard, not a feature reduction to match the mockup's
simpler single-panel layout.

Fixed match-score-panel.test.tsx's no-signal-state assertion, which
expected the removed inline "—" placeholder; restored it outside the
ring's conditional render.

job-tracker-ui/src/components/JobDetailsDialog.tsx

@@ -10,7 +10,6 @@ import {
   DialogTitle,
   FormControl,
   InputLabel,
-  LinearProgress,
   MenuItem,
   Select,
   Tab,
@@ -1229,27 +1228,35 @@ function MatchScoreCard({ score, loading }: { score: MatchScore | null; loading:
 
   return (
     <Box sx={{ p: 1.75, mb: 2, borderRadius: 3, border: "1px solid", borderColor: "divider", backgroundColor: "background.default" }}>
-      <Box sx={{ display: "flex", justifyContent: "space-between", alignItems: "center", gap: 1, flexWrap: "wrap", mb: 1 }}>
-        <Box sx={{ display: "flex", alignItems: "baseline", gap: 1 }}>
-          <Typography variant="h4" sx={{ fontWeight: 800, fontVariantNumeric: "tabular-nums" }}>{score.hasEnoughSignal ? `${score.score}%` : "—"}</Typography>
-          <Typography variant="overline">{t("matchScoreTitle")}</Typography>
-        </Box>
-        <Box sx={{ display: "flex", gap: 1, flexWrap: "wrap", alignItems: "center" }}>
-          <Chip size="small" color={color === "inherit" ? "default" : color} label={bandLabel} />
-          <Chip size="small" variant="outlined" label={t("matchScoreKeywordsCovered", { matched: score.matchedCount, total: score.totalKeywords })} />
+      <Box sx={{ display: "flex", gap: 2.5, alignItems: "center", flexWrap: "wrap", mb: 1.5 }}>
+        {score.hasEnoughSignal ? (
+          <Box sx={{ position: "relative", width: 92, height: 92, flexShrink: 0 }}>
+            <CircularProgress variant="determinate" value={100} size={92} thickness={4} sx={{ color: "divider", position: "absolute" }} />
+            <CircularProgress
+              variant="determinate"
+              value={score.score}
+              size={92}
+              thickness={4}
+              color={color === "inherit" ? "primary" : color}
+              sx={{ position: "absolute", "& .MuiCircularProgress-circle": { strokeLinecap: "round" } }}
+            />
+            <Box sx={{ position: "absolute", inset: 0, display: "flex", flexDirection: "column", alignItems: "center", justifyContent: "center" }}>
+              <Typography variant="h6" sx={{ fontWeight: 800, fontVariantNumeric: "tabular-nums", lineHeight: 1 }}>{score.score}%</Typography>
+              <Typography variant="caption" sx={{ color: "text.secondary" }}>{t("matchScoreTitle")}</Typography>
+            </Box>
+          </Box>
+        ) : (
+          <Typography variant="h4" sx={{ fontWeight: 800 }}>—</Typography>
+        )}
+        <Box sx={{ flex: 1, minWidth: 200 }}>
+          {!score.hasEnoughSignal ? <Typography variant="body2" sx={{ color: "text.secondary", mb: 1 }}>{t("matchScoreNoSignal")}</Typography> : null}
+          <Box sx={{ display: "flex", gap: 1, flexWrap: "wrap", alignItems: "center" }}>
+            <Chip size="small" color={color === "inherit" ? "default" : color} label={bandLabel} />
+            <Chip size="small" variant="outlined" label={t("matchScoreKeywordsCovered", { matched: score.matchedCount, total: score.totalKeywords })} />
+          </Box>
+          <Typography variant="caption" sx={{ color: "text.secondary", display: "block", mt: 1 }}>{t("matchScoreDeterministicHint")}</Typography>
         </Box>
       </Box>
-      {score.hasEnoughSignal ? (
-        <LinearProgress
-          variant="determinate"
-          value={score.score}
-          color={color === "inherit" ? "primary" : color}
-          sx={{ height: 8, borderRadius: 4, mb: 1.5 }}
-        />
-      ) : (
-        <Typography variant="body2" sx={{ color: "text.secondary", mb: 1 }}>{t("matchScoreNoSignal")}</Typography>
-      )}
-      <Typography variant="caption" sx={{ color: "text.secondary", display: "block", mb: 1 }}>{t("matchScoreDeterministicHint")}</Typography>
       <Box sx={{ display: "grid", gridTemplateColumns: { xs: "1fr", md: "1fr 1fr" }, gap: 1.5 }}>
         <Box>
           <Typography variant="overline">{t("matchScoreMatched")}</Typography>