UX-45: Home price chart draws one bar per price step the add-on uses

With 15-minute prices the chart now has one bar per quarter (92/96/100),
not hour averages; hourly and static tariffs still draw one bar per hour.
Cheap and dear marks come from the kept priceruns result (battery modes
on) or the arbitrage verdict's two points (off), not a thirds split.
A missing quarter is an empty bar. Removes plan.average_tip (EN/NL).

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

goodwe_controller/app/static/app.css

@@ -78,6 +78,8 @@ h2{font-size:15px;margin:0 0 10px;font-weight:650}
 .bars i.cheap{background:var(--cheap)}
 /* not by colour alone: expensive hours are striped, estimates are faded */
 .bars i.dear{background:repeating-linear-gradient(135deg,var(--dear) 0 4px,color-mix(in srgb,var(--dear) 60%,var(--card)) 4px 7px)}
+.bars.fine{gap:1px}
+.bars.fine i{border-radius:1px 1px 0 0}
 .bars i.est{opacity:.55}
 .bars i.none{background:none;border-bottom:2px dotted var(--faint);height:2px!important}
 .lane{position:relative;height:18px;margin-top:4px;background:var(--bg);border-radius:4px}