Add staggered-start car call-outs and a per-driver done indicator

Staggered-start qualifying heats now announce each car's transponder
number in grid order (~3s apart) right after the official start,
matching what a track announcer does when releasing cars one at a
time; mass/position starts are unaffected. The Timing leaderboard and
every overlay variant now also show a green "Done" flag next to a
driver's name once their own personal timing window (which already
started at their own first crossing) has elapsed, even while the
session is still running for other drivers.

Also confirmed two things already worked correctly: finals already
always start everyone together with the shared countdown/lights/tone
sequence, and practice's time-up announcement already says "finish
the lap you are on" - only a "2 minutes remaining" cue is genuinely
missing from the existing 1min/30s/10s ladder, left as an open
question for the user.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/timing_views.js

@@ -291,7 +291,7 @@ function renderLeaderboard(rows, deps) {
         <tr data-sort-values="${sortValuesAttribute([idx + 1, row.displayName || row.driverName, row.subLabel || row.carName, row.transponder, row.laps, row.resultDisplay, row.lastLapMs || null, row.bestLapMs || null, row.leaderGap || row.gap || null, row.gapAhead || null, row.lapDelta || null, row.lastSplitMs || null, [Number(row.pitStops || 0), Number(row.totalPitMs || 0)]])}" class="${row.invalidPending ? "leaderboard-invalid" : ""}">
           <td><span class="pos-pill ${posClass}">${idx + 1}</span></td>
           <td>
-            <div class="table-primary">${escapeHtml(row.displayName || row.driverName)}</div>
+            <div class="table-primary">${escapeHtml(row.displayName || row.driverName)}${row.personalTimeUp ? ` <span class="pill pill-green">🏁 ${t("timing.personal_time_up")}</span>` : ""}</div>
             ${row.teamId ? `<div class="table-subnote">${t("overlay.active_member")}: ${escapeHtml(formatTeamActiveMemberLabel(row))}</div>` : ""}
             ${getManualCorrectionSummary(row) ? `<div class="table-subnote">${escapeHtml(getManualCorrectionSummary(row))}</div>` : ""}
             ${row.invalidPending ? `<div class="table-subnote table-subnote-warn">${escapeHtml(row.invalidLabel)}${row.invalidLapMs ? ` • ${formatLap(row.invalidLapMs)}` : ""}</div>` : ""}