feat(case-ui): full-width tabs + parties popover + subject on title line

Chair-requested refinements to the case banner:
- Tabs now span the full band width via justify-between — wide gaps with the
  current 6 tabs, tightening as more are added (gap-2 no-overlap floor).
- Parties moved out of the always-on header line into a "צדדים" Popover, so the
  band is shorter and the tab content sits higher on the page.
- Case subject (title) moved up onto the case-number line in a smaller font,
  instead of its own line below.

tsc --noEmit + eslint clean.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

web-ui/src/app/cases/[caseNumber]/page.tsx

@@ -80,10 +80,12 @@ export default function CaseDetailPage({
   ];
 
   // V2 "segmented" tab strip (X17): each tab a pill, active = raised white card.
+  // Spread full-width via justify-between (chair request) — wide gaps with few
+  // tabs, tightening as more are added; gap-2 is the no-overlap floor.
   const tabsList = (
     <TabsList
       variant="line"
-      className="!h-auto gap-1.5 p-0 flex-wrap justify-start"
+      className="!h-auto w-full gap-2 p-0 justify-between"
     >
       {tabDefs.map(([value, label, Icon]) => (
         <TabsTrigger

web-ui/src/components/cases/case-header.tsx

@@ -10,17 +10,14 @@ import {
   APPEAL_SUBTYPE_LABELS,
   isBlamSubtype,
 } from "@/lib/practice-area";
+import {
+  Popover,
+  PopoverContent,
+  PopoverTrigger,
+} from "@/components/ui/popover";
+import { Users } from "lucide-react";
 import type { CaseDetail } from "@/lib/api/cases";
 
-function partiesLine(data?: CaseDetail): string | null {
-  const appellant = data?.appellants?.filter(Boolean) ?? [];
-  const respondent = data?.respondents?.filter(Boolean) ?? [];
-  const parts: string[] = [];
-  if (appellant.length) parts.push(`עוררת: ${appellant.join(", ")}`);
-  if (respondent.length) parts.push(`משיבה: ${respondent.join(", ")}`);
-  return parts.length ? parts.join(" · ") : null;
-}
-
 /**
  * Case header — parchment band (IA-redesign mockup 17): full-bleed band with
  * the case title + status/type chips inline, a parties line, the case actions
@@ -38,7 +35,9 @@ export function CaseHeader({
   actions?: ReactNode;
   tabs?: ReactNode;
 }) {
-  const parties = partiesLine(data);
+  const appellants = data?.appellants?.filter(Boolean) ?? [];
+  const respondents = data?.respondents?.filter(Boolean) ?? [];
+  const hasParties = appellants.length > 0 || respondents.length > 0;
   const isBlam =
     data?.proceeding_type === 'בל"מ' || isBlamSubtype(data?.appeal_subtype);
 
@@ -61,6 +60,12 @@ export function CaseHeader({
             <span className="tabular-nums">
               {data?.proceeding_type ?? "ערר"} {data?.case_number ?? "—"}
             </span>
+            {/* case subject on the same line, smaller font (chair request) */}
+            {data?.title && (
+              <span className="text-navy/75 text-lg font-semibold leading-snug">
+                {data.title}
+              </span>
+            )}
             {data?.status && <StatusBadge status={data.status} />}
             {data?.archived_at && (
               <Badge
@@ -92,27 +97,44 @@ export function CaseHeader({
             )}
           </h1>
 
-          {/* case title / subject under the heading */}
-          {data?.title && (
-            <p className="text-navy/90 text-base font-semibold mt-2 max-w-3xl leading-snug">
-              {data.title}
-            </p>
-          )}
-          {/* parties line (mockup .parties) — clamped to 2 lines so a long list
-              of appellants/respondents doesn't grow the band; full text on hover. */}
-          {parties ? (
-            <p className="text-ink-soft text-sm mt-1.5 max-w-3xl line-clamp-2" title={parties}>
-              {parties}
-            </p>
-          ) : data?.subject ? (
-            <p className="text-ink-soft text-sm mt-1.5 max-w-3xl leading-relaxed line-clamp-2"
-               title={data.subject}>
-              {data.subject}
-            </p>
-          ) : null}
-
-          {/* case actions — kept verbatim, moved into the band */}
+          {/* case actions — parties now live in a popover (chair request) so
+              they don't push the tab content down the page. */}
           <div className="flex items-center gap-2 flex-wrap mt-3">
+            {hasParties && (
+              <Popover>
+                <PopoverTrigger asChild>
+                  <button
+                    type="button"
+                    className="inline-flex items-center gap-1.5 rounded-md border border-rule bg-surface px-3 py-1.5 text-[0.82rem] font-semibold text-ink-soft hover:bg-parchment transition-colors"
+                  >
+                    <Users className="w-3.5 h-3.5" />
+                    צדדים
+                  </button>
+                </PopoverTrigger>
+                <PopoverContent align="start" className="w-72 p-3 space-y-2.5 text-sm">
+                  {appellants.length > 0 && (
+                    <div>
+                      <div className="text-[0.7rem] font-bold text-gold-deep uppercase tracking-wider mb-1">
+                        עוררים
+                      </div>
+                      <ul className="space-y-0.5 text-ink-soft">
+                        {appellants.map((a, i) => <li key={`a${i}`}>{a}</li>)}
+                      </ul>
+                    </div>
+                  )}
+                  {respondents.length > 0 && (
+                    <div>
+                      <div className="text-[0.7rem] font-bold text-gold-deep uppercase tracking-wider mb-1">
+                        משיבים
+                      </div>
+                      <ul className="space-y-0.5 text-ink-soft">
+                        {respondents.map((r, i) => <li key={`r${i}`}>{r}</li>)}
+                      </ul>
+                    </div>
+                  )}
+                </PopoverContent>
+              </Popover>
+            )}
             {data?.case_number && (
               <CaseArchiveAction
                 caseNumber={data.case_number}