chore(assets): migrate zibll img resources to assets/img

Copy Zibll's widget/visual reference assets into assets/img for
1:1 replication (Phase 5 resource migration):
- slider-bg.jpg, slider-layer-1.png, slider-layer-2.png
- user_t.jpg, avatar-default.png
- null*.svg (null, null-2, null-cap, null-love, null-money,
  null-order, null-post, null-search, null-set, null-user)
- thumbnail*.svg (thumbnail, thumbnail-lg, thumbnail-sm,
  thumbnail-null)
- medal/ (31 medal-*.svg badges)

These are reference placeholders to be progressively replaced;
no CSF framework ported. user-level-1..10.png already present.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

assets/img/null-cap.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" xml:space="preserve" id="svg1109" width="800" height="600" x="0" y="0" version="1.1"><defs id="defs1113"><linearGradient id="linearGradient1362" x1="362.782" x2="446.348" y1="386.985" y2="386.985" gradientUnits="userSpaceOnUse"><stop id="stop1358" offset=".288" style="stop-color:#fff;stop-opacity:.18410042"/><stop id="stop1364" offset=".587" style="stop-color:#edf2f7;stop-opacity:0"/><stop id="stop1360" offset="1" style="stop-color:#d8e3ef;stop-opacity:0"/></linearGradient><linearGradient xlink:href="#linearGradient1362" id="linearGradient1149" x1="418.785" x2="417.68" y1="398.895" y2="724.862" gradientUnits="userSpaceOnUse"/></defs><style id="style833" type="text/css">.st20{fill:#c6d5e6}.st33{fill:#f8b62d}.st34{fill:#e6e8e8}</style><g id="背景_28_" transform="matrix(1.07917 0 0 1.1122 -32.429 -99.873)"><linearGradient id="SVGID_1_" x1="256.573" x2="256.573" y1="422.067" y2="325.279" gradientUnits="userSpaceOnUse"><stop id="stop863" offset="0" style="stop-color:#fff"/><stop id="stop865" offset="1" style="stop-color:#dbe3ee"/></linearGradient><path id="path868" d="M271.03 328.68v-3.41h-29.5v3.96h-6.48v92.83h43.05v-93.38zm3.34 82.74h-36.04v-2.75h36.04zm0-12.67h-36.04V396h36.04zm0-12.68h-36.04v-2.75h36.04zm0-12.34h-36.04v-2.75h36.04zm0-12.32h-36.04v-2.75h36.04zm0-12.67h-36.04v-2.75h36.04zm0-12.35h-36.04v-2.75h36.04z" style="fill:url(#SVGID_1_)"/><linearGradient id="SVGID_2_" x1="191.956" x2="191.956" y1="480.059" y2="263.57" gradientUnits="userSpaceOnUse"><stop id="stop870" offset="0" style="stop-color:#fff"/><stop id="stop872" offset="1" style="stop-color:#dbe3ee"/></linearGradient><path id="path875" d="M213.05 380.5V272.31H180.3v-8.74h-13.86v53.33h-3.73v163.16h58.51V380.5Zm-24.5 31.8h-8.26v-8.01h8.26zm0-12.52h-8.26v-8.01h8.26zm0-12.48h-8.26v-8.01h8.26zm0-12.44h-8.26v-8.01h8.26zm0-12.53h-8.26v-8.01h8.26zm0-25h-8.26v-8.01h8.26zm0-12.53h-8.26v-8.01h8.26zm0-12.47h-8.26v-8.01h8.26zm0-12.44h-8.26v-8.01h8.26zm0-12.53h-8.26v-8.01h8.26zM200.9 412.3h-8.26v-8.01h8.26zm0-12.52h-8.26v-8.01h8.26zm0-12.48h-8.26v-8.01h8.26zm0-12.44h-8.26v-8.01h8.26zm0-12.53h-8.26v-8.01h8.26zm0-25h-8.26v-8.01h8.26zm0-12.53h-8.26v-8.01h8.26zm0-12.47h-8.26v-8.01h8.26zm0-12.44h-8.26v-8.01h8.26zm0-12.53h-8.26v-8.01h8.26z" style="fill:url(#SVGID_2_)"/><linearGradient id="SVGID_3_" x1="567.738" x2="567.738" y1="437.38" y2="280.899" gradientUnits="userSpaceOnUse"><stop id="stop877" offset="0" style="stop-color:#fff"/><stop id="stop879" offset="1" style="stop-color:#dbe3ee"/></linearGradient><path id="path882" d="M535.36 437.38c.36-4.65 0-156.48 0-156.48h18.53v33.71h29.5v70.45h16.73v52.32z" style="fill:url(#SVGID_3_)"/><linearGradient id="SVGID_4_" x1="630.263" x2="630.263" y1="460.05" y2="290.309" gradientUnits="userSpaceOnUse"><stop id="stop884" offset="0" style="stop-color:#fff"/><stop id="stop886" offset="1" style="stop-color:#dbe3ee"/></linearGradient><path id="path889" d="M656.57 369.23v-4.85h-5v-42.33h-12.2v-4.7h-8.23v-6.91h-4.29V290.3h-3.09v20.28h-3.94v6.91h-12.2v11.32h-7.05v131.23h59.38v-90.82h-3.38zm-45.51 52.79h-4.02v-15.24h4.02zm0-18.65h-4.02v-15.24h4.02zm0-18.65h-4.02v-15.24h4.02zm0-18.99h-4.02V350.5h4.02zm0-18.98h-4.02v-15.24h4.02zm8.28 75.27h-4.02v-15.24h4.02zm0-18.65h-4.02v-15.24h4.02zm0-18.65h-4.02v-15.24h4.02zm0-18.99h-4.02V350.5h4.02zm0-18.98h-4.02v-15.24h4.02zm8.28 75.27h-4.02v-15.24h4.02zm0-18.65h-4.02v-15.24h4.02zm0-18.65h-4.02v-15.24h4.02zm0-18.99h-4.02V350.5h4.02zm0-18.98h-4.02v-15.24h4.02zm8.28 75.27h-4.02v-15.24h4.02zm0-18.65h-4.02v-15.24h4.02zm0-18.65h-4.02v-15.24h4.02zm0-18.99h-4.02V350.5h4.02zm0-18.98h-4.02v-15.24h4.02zm8.28 75.27h-4.02v-15.24h4.02zm0-18.65h-4.02v-15.24h4.02zm0-18.65h-4.02v-15.24h4.02zm0-18.99h-4.02V350.5h4.02zm0-18.98h-4.02v-15.24h4.02z" style="fill:url(#SVGID_4_)"/><linearGradient id="SVGID_5_" x1="121.55" x2="121.55" y1="502.128" y2="351.615" gradientUnits="userSpaceOnUse"><stop id="stop891" offset="0" style="stop-color:#fff;stop-opacity:.82008368"/><stop id="stop893" offset="1" style="stop-color:#edf1f9"/></linearGradient><path id="polygon896" d="M140.44 411.86h7.74v90.27H94.92v-89.55h10.26v-45.69l35.26-15.27z" style="fill:url(#SVGID_5_)"/><linearGradient id="SVGID_6_" x1="684.223" x2="684.223" y1="485.523" y2="362.391" gradientUnits="userSpaceOnUse"><stop id="stop898" offset="0" style="stop-color:#fff"/><stop id="stop900" offset="1" style="stop-color:#edf1f9"/></linearGradient><path id="polygon903" d="M668.75 485.52V362.39l30.94 14.97v108.16z" style="fill:url(#SVGID_6_)"/><linearGradient id="SVGID_7_" x1="127.514" x2="127.514" y1="229.821" y2="165.28" gradientUnits="userSpaceOnUse"><stop id="stop905" offset=".233" style="stop-color:#fff;stop-opacity:.12970711"/><stop id="stop907" offset="1" style="stop-color:#d3dfee"/></linearGradient><path id="path910" d="M72.903 180.545s9.34-25.48 32.3-15.48c5.3-5.38 11.86-9.29 20.73-7.53 8.87 1.77 14.59 8.41 16.53 12.83-16.53-12.83 25.04.61 25.04 23.7s-26.94 22.65-28.89 20.82c-2Line truncated