Render research prose as Markdown with RTL tables

The analysis-and-research.md content has markdown tables (ציר דיוני)
and inline formatting like **label:** strong runs, which were
rendering as raw pipes and dashes because the compose page used
whitespace-pre-line on plain text.

Add a reusable <Markdown> component backed by react-markdown +
remark-gfm with a custom `components` map that styles paragraphs,
lists, blockquotes, strong runs, and especially GFM tables for RTL
+ aligned columns:

- table: table-auto + border-collapse, wrapped in overflow-x-auto
  so very wide tables don't push the parent card out
- th: whitespace-nowrap so the header row sets column widths and
  every row border lines up row-to-row
- everything text-right + the whole block gets dir="rtl" at the root

Use it in three places on the compose screen:
- ProseSection (represented_party, procedural_background,
  agreed_facts, disputed_facts)
- Conclusions card
- SubsectionCard field content — threshold_claims and issues have
  the same markdown shape in their fields[]

react-markdown + remark-gfm added (~30KB gzipped).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

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

@@ -8,6 +8,7 @@ import { Button } from "@/components/ui/button";
 import { Skeleton } from "@/components/ui/skeleton";
 import { SubsectionCard } from "@/components/compose/subsection-card";
 import { PrecedentsSection } from "@/components/compose/precedents-section";
+import { Markdown } from "@/components/ui/markdown";
 import { useCase } from "@/lib/api/cases";
 import { useResearchAnalysis } from "@/lib/api/research";
 import { useCasePrecedents } from "@/lib/api/precedents";
@@ -19,9 +20,7 @@ function ProseSection({ title, content }: { title: string; content?: string }) {
       <h3 className="text-[0.78rem] uppercase tracking-[0.08em] text-gold-deep font-semibold">
         {title}
       </h3>
-      <p className="text-sm text-ink-soft leading-relaxed whitespace-pre-line prose">
-        {content.trim()}
-      </p>
+      <Markdown content={content.trim()} />
     </section>
   );
 }
@@ -216,11 +215,9 @@ export default function ComposePage({
 
               {analysis.data.conclusions?.trim() && (
                 <Card className="bg-gold-wash border-gold/40 shadow-sm">
-                  <CardContent className="px-6 py-5 space-y-2">
+                  <CardContent className="px-6 py-5 space-y-3">
                     <h2 className="text-gold-deep text-xl mb-0">מסקנות</h2>
-                    <p className="text-sm text-ink leading-relaxed whitespace-pre-line prose">
-                      {analysis.data.conclusions.trim()}
-                    </p>
+                    <Markdown content={analysis.data.conclusions.trim()} />
                   </CardContent>
                 </Card>
               )}