fix(reports): switching editions replaces the reader instead of stacking it (BUG-1126)

The reader and the fact tables were siblings keyed by the same language, so
React left the first edition's reader on screen and appended the new one.
Distinct keys per sibling; whole-page switch test with real engine fact tables.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N4f2nya58RoRu4yEmJgRGE

frontend/src/components/personal-report/personal-report-page.tsx

@@ -564,9 +564,10 @@ export function PersonalReportPage({ reportId, initialLanguage = "zh" }: { repor
           onLanguageChange={switchLanguage}
         />
         <div className="personal-report-reader-body" lang={shown === "en" ? "en" : "zh-CN"}>
-          <PersonalReportMarkdownView key={shown} language={shown} markdown={markdown} drawnThrough={drawnThrough} />
+          {/* Siblings remount per edition under distinct keys; a shared key left the old edition on screen (BUG-1126). */}
+          <PersonalReportMarkdownView key={`markdown-${shown}`} language={shown} markdown={markdown} drawnThrough={drawnThrough} />
           {state.calculationCharts && <ReportCalculationCharts charts={state.calculationCharts} language={shown} />}
-          {factTables && <ReportFactTables key={shown} language={shown} tables={factTables} />}
+          {factTables && <ReportFactTables key={`facts-${shown}`} language={shown} tables={factTables} />}
         </div>
       </div>
     </>