Add dog flow simulation and fix button grid centering

- Add flow-over-dog entry (4 B200s on HiPerGator, 1h) to landing
  page and Doxygen gallery with thumbnail
- Add shock-helium entry to landing page inline sims array (was
  only in simulations.json)
- Fix nav button grid: grid-cols-7 → grid-cols-6 after API button
  removal

YouTube: https://youtube.com/watch?v=Xhvr2kkQa30

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: sbryngelson

docs/index.html

@@ -55,6 +55,7 @@
             // Aerodynamics
             { name: "Flow over an airfoil (vorticity)",  image: "res/simulations/g.png", computer: "Delta",    computerUrl: "https://www.ncsa.illinois.edu/research/project-highlights/delta/",              accelerators: "128 A100s", walltime: "19h",     source: "https://www.youtube.com/watch?v=FvAgnBW59cY" },
             { name: "Pitching airfoil (3D)",             image: "res/simulations/m.png", computer: "Phoenix",  computerUrl: "https://www.pace.gatech.edu/",                                                 accelerators: "1 A100",    walltime: "5h",      source: "https://www.youtube.com/watch?v=2XH-9MumDHU" },
+            { name: "Flow over a dog (pressure)",        image: "res/simulations/u.png", computer: "HiPerGator", computerUrl: "https://www.rc.ufl.edu/about/hipergator/",                                   accelerators: "4 B200s",   walltime: "1h",      source: "https://www.youtube.com/watch?v=Xhvr2kkQa30" },
             // Shock-droplet
             { name: "Shedding water droplet",            image: "res/simulations/a.png", computer: "Summit",   computerUrl: "https://www.olcf.ornl.gov/summit/",                                            accelerators: "960 V100s", walltime: "4h",      source: "https://www.youtube.com/watch?v=Gjj-qZkXcrg" },
             // Biomedical & acoustics
@@ -71,6 +72,7 @@
             // Fundamentals
             { name: "Breakup of vibrated interface",     image: "res/simulations/f.png", computer: "Summit",   computerUrl: "https://www.olcf.ornl.gov/summit/",                                            accelerators: "128 V100s", walltime: "4h",      source: "https://www.youtube.com/watch?v=XQ3g1oSg8mc" },
             { name: "Viscous Taylor-Green vortex",       image: "res/simulations/h.png", computer: "Delta",    computerUrl: "https://www.ncsa.illinois.edu/research/project-highlights/delta/",              accelerators: "128 A100s", walltime: "17h",     source: "https://www.youtube.com/watch?v=7i2h08dlDQw" },
+            { name: "Mach 1.5 shock-helium bubble",      image: "res/simulations/t.png", computer: "Phoenix",  computerUrl: "https://www.pace.gatech.edu/",                                                 accelerators: "1 A100",    walltime: "1h",      source: "https://www.youtube.com/watch?v=zDJoe0NYZsQ" },
         ];
 
         const scalings = [
@@ -172,7 +174,7 @@
                 </div>
             </div>
             <div class="flex mx-auto">
-                <div class="justify-center grid grid-cols-2 sm:grid-cols-3 lg:grid-cols-7 gap-x-4 md:gap-x-8 text-md md:text-xl text-center text-white font-medium">
+                <div class="justify-center grid grid-cols-2 sm:grid-cols-3 lg:grid-cols-6 gap-x-4 md:gap-x-8 text-md md:text-xl text-center text-white font-medium">
                     <a class="px-4 flex flex-row items-center py-4 border-b-2 hover:border-amber-400" href="https://github.com/MFlowCode/MFC">
                         <i class="pr-4 fa-brands fa-github"></i>
                         <span class="flex-1">GitHub</span>

docs/res/simulations/u.png

@@ -17,5 +17,6 @@
     { "name": "Euler-Lagrange particle cloud",       "category": "Bubble dynamics",        "image": "res/simulations/s.png", "computer": "Phoenix",  "computerUrl": "https://www.pace.gatech.edu/",                                                 "accelerators": "8 A100s",   "walltime": "<1h",  "source": "https://www.youtube.com/watch?v=RoT-yC5Lxmg" },
     { "name": "Breakup of vibrated interface",       "category": "Fundamentals",           "image": "res/simulations/f.png", "computer": "Summit",   "computerUrl": "https://www.olcf.ornl.gov/summit/",                                            "accelerators": "128 V100s", "walltime": "4h",   "source": "https://www.youtube.com/watch?v=XQ3g1oSg8mc" },
     { "name": "Viscous Taylor-Green vortex",         "category": "Fundamentals",           "image": "res/simulations/h.png", "computer": "Delta",    "computerUrl": "https://www.ncsa.illinois.edu/research/project-highlights/delta/",              "accelerators": "128 A100s", "walltime": "17h",  "source": "https://www.youtube.com/watch?v=7i2h08dlDQw" },
-    { "name": "Mach 1.5 shock-helium bubble",        "category": "Fundamentals",           "image": "res/simulations/t.png", "computer": "Phoenix",  "computerUrl": "https://www.pace.gatech.edu/",                                                 "accelerators": "1 A100",    "walltime": "1h",   "source": "https://www.youtube.com/watch?v=zDJoe0NYZsQ" }
+    { "name": "Mach 1.5 shock-helium bubble",        "category": "Fundamentals",           "image": "res/simulations/t.png", "computer": "Phoenix",  "computerUrl": "https://www.pace.gatech.edu/",                                                 "accelerators": "1 A100",    "walltime": "1h",   "source": "https://www.youtube.com/watch?v=zDJoe0NYZsQ" },
+    { "name": "Flow over a dog (pressure)",          "category": "Aerodynamics",           "image": "res/simulations/u.png", "computer": "HiPerGator", "computerUrl": "https://www.rc.ufl.edu/about/hipergator/",                                   "accelerators": "4 B200s",   "walltime": "1h",   "source": "https://www.youtube.com/watch?v=Xhvr2kkQa30" }
 ]