web(plastic-health): add 4 evidence screenshots with Chinese annotations for office water risk factors

- ref-pet-sources.png: PET瓶620万颗粒/升 对应风险①桶身老化
- ref-hot-water-antimony.png: 70°C高温锑/BPA释放 对应风险②高温加热
- ref-heat-sunlight.png: UV/高温加速降解 对应风险③存放暴晒
- ref-ohio-state.png: 瓶装水塑料为自来水2-3倍 对应风险④密封垫磨损

Each English-page screenshot includes injected Chinese translation annotations.

web/plastic-health.html

@@ -675,19 +675,35 @@
       </div>
     </div>
 
-    <!-- 截图：饮用水中微塑料 -->
+    <!-- 截图：四大风险对应证据 -->
     <div style="display:grid;grid-template-columns:1fr 1fr;gap:1rem;margin:1.5rem 0;">
       <div>
-        <a href="img/ref-sciencedaily.png" target="_blank">
-          <img src="img/ref-sciencedaily.png" alt="ScienceDaily: Bottled water microplastics study" style="width:100%;border-radius:12px;border:1px solid #E2E8F0;box-shadow:0 4px 12px rgba(0,0,0,0.08);">
+        <a href="img/ref-pet-sources.png" target="_blank">
+          <img src="img/ref-pet-sources.png" alt="PET瓶污染源" style="width:100%;border-radius:12px;border:1px solid #E2E8F0;box-shadow:0 4px 12px rgba(0,0,0,0.08);">
         </a>
-        <p style="font-size:0.75rem;color:var(--text-muted);margin-top:0.3rem;">↑ Concordia 大学综述：瓶装水用户年多摄入9万微塑料颗粒<br><a href="https://www.sciencedaily.com/releases/2025/10/251006051131.htm" target="_blank" style="color:var(--blue);">来源: ScienceDaily 2025</a></p>
+        <p style="font-size:0.85rem;color:var(--text-primary);margin-top:0.4rem;font-weight:600;">📌 对应风险①：桶身老化/瓶身材料</p>
+        <p style="font-size:0.75rem;color:var(--text-muted);">CCWIN 2026 国内15品牌检测：PET瓶620万颗粒/升，污染始于制造、运输、储存<br><a href="http://www.ccwin.cn/article-87006-1.html" target="_blank" style="color:var(--blue);">来源: 中国商业网 2026 →</a></p>
       </div>
       <div>
-        <a href="img/ref-who-report.png" target="_blank">
-          <img src="img/ref-who-report.png" alt="WHO Microplastics in drinking-water report" style="width:100%;border-radius:12px;border:1px solid #E2E8F0;box-shadow:0 4px 12px rgba(0,0,0,0.08);">
+        <a href="img/ref-hot-water-antimony.png" target="_blank">
+          <img src="img/ref-hot-water-antimony.png" alt="ScienceDaily: 高温释放锑/BPA" style="width:100%;border-radius:12px;border:1px solid #E2E8F0;box-shadow:0 4px 12px rgba(0,0,0,0.08);">
         </a>
-        <p style="font-size:0.75rem;color:var(--text-muted);margin-top:0.3rem;">↑ WHO 2019 技术报告：饮用水中微塑料污染普遍存在<br><a href="https://www.who.int/publications/i/item/9789241516198" target="_blank" style="color:var(--blue);">来源: 世界卫生组织</a></p>
+        <p style="font-size:0.85rem;color:var(--text-primary);margin-top:0.4rem;font-weight:600;">📌 对应风险②：饮水机高温加热</p>
+        <p style="font-size:0.75rem;color:var(--text-muted);">UF/南京大学研究：PET瓶70°C高温下锑和BPA释放量显著增加<br><a href="https://www.sciencedaily.com/releases/2014/09/140922110139.htm" target="_blank" style="color:var(--blue);">来源: ScienceDaily 2014 →</a></p>
+      </div>
+      <div>
+        <a href="img/ref-heat-sunlight.png" target="_blank">
+          <img src="img/ref-heat-sunlight.png" alt="Ohio State: 热量和紫外线加速降解" style="width:100%;border-radius:12px;border:1px solid #E2E8F0;box-shadow:0 4px 12px rgba(0,0,0,0.08);">
+        </a>
+        <p style="font-size:0.85rem;color:var(--text-primary);margin-top:0.4rem;font-weight:600;">📌 对应风险③：暴晒温度波动</p>
+        <p style="font-size:0.75rem;color:var(--text-muted);">Ohio State：紫外线与高温加速塑料降解，BPA-free瓶子也会释放化学物质<br><a href="https://health.osu.edu/health/general-health/reducing-microplastics-better-health" target="_blank" style="color:var(--blue);">来源: 俄亥俄州立大学 2025 →</a></p>
+      </div>
+      <div>
+        <a href="img/ref-ohio-state.png" target="_blank">
+          <img src="img/ref-ohio-state.png" alt="Ohio State: 瓶装水vs自来水" style="width:100%;border-radius:12px;border:1px solid #E2E8F0;box-shadow:0 4px 12px rgba(0,0,0,0.08);">
+        </a>
+        <p style="font-size:0.85rem;color:var(--text-primary);margin-top:0.4rem;font-weight:600;">📌 对应风险④：密封垫/聪明座磨损</p>
+        <p style="font-size:0.75rem;color:var(--text-muted);">Ohio State：瓶装水塑料含量为自来水2-3倍，260万~1150万颗粒/升，半数可入血<br><a href="https://studyfinds.com/bottled-water-twice-plastic-contamination-tap-water/" target="_blank" style="color:var(--blue);">来源: Ohio State Univ. 2026 →</a></p>
       </div>
     </div>
   </div>