docs(assets): redesign waitlist SVG button with outlined Archivo typeface and brand palette

Replaces the plain oxblood-filled rectangle + system-font text SVG with a
polished button that matches the getcodegraph.com design language:

- Cream (#f7f6f2) rounded-rect background with a soft hairline border, 8px
  radius, 52px height
- Logo mark (graph triangle, mirrors favicon.svg) in ink/oxblood at left
- Hairline divider separating mark from label
- "Join the waitlist!" label rendered as vector outlines (Archivo Bold 760,
  17.5px) so the brand typeface renders correctly on GitHub, which blocks
  @font-face in statically-served SVGs
- Oxblood arrow at right

Adds assets/generate-waitlist.py (requires fonttools + brotli) so the SVG
can be regenerated from the landing-page's Archivo variable font. Updates
the README img height from 44→52 to match the new geometry.

assets/waitlist.svg

@@ -1,6 +1,22 @@
-<svg xmlns="http://www.w3.org/2000/svg" width="192" height="44" viewBox="0 0 192 44" role="img" aria-label="Join the waitlist">
-  <rect x="0.5" y="0.5" width="191" height="43" fill="#7a201a" stroke="#5e1812"/>
-  <text x="96" y="27.5" text-anchor="middle"
-        font-family="-apple-system, BlinkMacSystemFont, 'Helvetica Neue', 'Segoe UI', Arial, sans-serif"
-        font-size="16" font-weight="600" fill="#f7f6f2">Join the waitlist<tspan dx="8">&#8594;</tspan></text>
+<svg xmlns="http://www.w3.org/2000/svg" width="285.58" height="52" viewBox="0 0 285.58 52" role="img" aria-label="Join the waitlist!">
+  <title>Join the waitlist!</title>
+  <rect x="0.5" y="0.5" width="284.58" height="51" rx="8" fill="#f7f6f2" stroke="#d6d3c8"/>
+  <!-- logo mark (mirrors static/favicon.svg) -->
+  <g stroke="#16150f" stroke-width="2.02" stroke-linecap="round" fill="none">
+    <line x1="35.5" y1="18.43" x2="27.43" y2="33.57"/>
+    <line x1="35.5" y1="18.43" x2="43.58" y2="33.57"/>
+    <line x1="27.43" y1="33.57" x2="43.58" y2="33.57"/>
+  </g>
+  <circle cx="35.5" cy="18.43" r="3.43" fill="#7a201a"/>
+  <circle cx="27.43" cy="33.57" r="3.43" fill="#f7f6f2" stroke="#16150f" stroke-width="2.02"/>
+  <circle cx="43.58" cy="33.57" r="3.43" fill="#f7f6f2" stroke="#16150f" stroke-width="2.02"/>
+  <!-- hairline divider -->
+  <line x1="64.01" y1="13" x2="64.01" y2="39" stroke="#d6d3c8"/>
+  <!-- label (outlined Archivo, no font dependency) -->
+  <path d="M87.06102188110353 32.21Q85.63705871582032 32.21 84.62491539001465 31.785816192626953Q83.61277206420898 31.361632385253905 83.07940444946288 30.503375091552734Q82.5460368347168 29.64511779785156 82.5460368347168 28.320831146240234V27.86544128417969H85.36731582641602V28.31360321044922Q85.36731582641602 29.122787017822265 85.77990043640136 29.505125274658205Q86.19248504638672 29.88746353149414 87.01042633056642 29.88746353149414Q87.80782348632813 29.88746353149414 88.21527206420899 29.3767244720459Q88.62272064208985 28.865985412597656 88.62272064208985 27.851360321044922V19.980544128417968H91.56573486328125V27.858588256835937Q91.56573486328125 29.33695587158203 91.03236724853517 30.303069839477537Q90.49899963378907 31.269183807373047 89.4919923400879 31.739591903686524Q88.48498504638673 32.21 87.06102188110353 32.21ZM98.52074981689454 32.21Q96.98683807373047 32.21 95.91040061950685 31.686522064208987Q94.83396316528321 31.16304412841797 94.26863967895508 30.09193016052246Q93.70331619262696 29.020816192626953 93.70331619262696 27.390272064208986Q93.70331619262696 25.742227935791014 94.26863967895508 24.679863967895507Q94.83396316528321 23.6175 95.91040061950685 23.094022064208986Q96.98683807373047 22.570544128417968 98.52074981689454 22.570544128417968Q100.06493362426758 22.570544128417968 101.13984901428223 23.094022064208986Q102.21476440429689 23.6175 102.78008789062501 24.679863967895507Q103.34541137695314 25.742227935791014 103.34541137695314 27.390272064208986Q103.34541137695314 29.020816192626953 102.78008789062501 30.09193016052246Q102.21476440429689 31.16304412841797 101.13984901428223 31.686522064208987Q100.06493362426758 32.21 98.52074981689454 32.21ZM98.52074981689454 30.207022247314452Q99.26678665161133 30.207022247314452 99.72882713317871 29.919411926269532Q100.1908676147461 29.63180160522461 100.40181983947754 29.065900802612305Q100.61277206420898 28.5 100.61277206420898 27.671786651611328V27.115985412597656Q100.61277206420898 26.287772064208983 100.40181983947754 25.71825729370117Q100.1908676147461 25.14874252319336 99.72882713317871 24.86113220214844Q99.26678665161133 24.573521881103517 98.52074981689454 24.573521881103517Q97.77471298217773 24.573521881103517 97.31628646850587 24.86113220214844Q96.85785995483398 25.14874252319336 96.64690773010254 25.71825729370117Q96.4359555053711 26.287772064208983 96.4359555053711 27.115985412597656V27.671786651611328Q96.4359555053711 28.5 96.64690773010254 29.065900802612305Q96.85785995483398 29.63180160522461 97.31628646850587 29.919411926269532Q97.77471298217773 30.207022247314452 98.52074981689454 30.207022247314452ZM105.29886032104493 21.500374908447263V19.333044128417967H107.99041137695313V21.500374908447263ZM105.29886032104493 32.0V22.78054412841797H107.99041137695313V32.0ZM110.39886032104492 32.0V22.78054412841797H112.62476440429687L112.82144821166992 24.077823486328125H112.94394821166992Q113.28063201904297 23.607227935791016 113.73467979431152 23.269022064208983Q114.18872756958008 22.930816192626953 114.75804740905761 22.75068016052246Q115.32736724853515 22.570544128417968 115.97791137695313 22.570544128417968Q116.94687454223633 22.570544128417968 117.63508041381836 22.925297775268554Q118.32328628540039 23.28005142211914 118.69383041381835 24.008963165283202Q119.06437454223632 24.737874908447264 119.06437454223632 25.8814631652832V32.0H116.36255142211914V26.280919036865235Q116.36255142211914 25.870426330566406 116.26325729370117 25.582816009521487Q116.1639631652832 25.295205688476564 115.97773887634278 25.104797592163088Q115.79151458740235 24.91438949584961 115.51626823425293 24.823275527954102Q115.24102188110352 24.732161560058593 114.8921615600586 24.732161560058593Q114.37248504638671 24.732161560058593 113.96655853271484 24.979635848999024Q113.56063201904297 25.22711013793945 113.32552169799806 25.648444747924806Q113.09041137695313 26.069779357910157 113.09041137695313 26.616088256835937V32.0ZM128.02073486328126 32.21Q127.12709518432618 32.21 126.53951805114747 31.91934555053711Q125.95194091796876 31.628691101074217 125.66756965637208 31.09132713317871Q125.38319839477539 30.553963165283204 125.38319839477539 29.83494857788086V24.783521881103514H124.20119110107422V22.78054412841797H125.47183807373047L126.0086247253418 20.114080963134764H128.07474945068358V22.78054412841797H129.81903610229492V24.783521881103514H128.07474945068358V29.25632385253906Q128.07474945068358 29.717787017822264 128.2672494506836 29.962404632568358Q128.4597494506836 30.207022247314452 128.93148468017577 30.207022247314452H129.81903610229492V31.91554412841797Q129.60066848754883 31.992772064208985 129.2818670654297 32.06125Q128.96306564331056 32.12972793579102 128.62885612487793 32.16986396789551Q128.29464660644533 32.21 128.02073486328126 32.21ZM131.6138603210449 32.0V19.333044128417967H134.30541137695312V23.79440444946289H134.42791137695312Q134.7254113769531 23.419676513671874 135.14959518432616 23.1505184173584Q135.5737789916992 22.881360321044923 136.093642959594Line truncated
+  <!-- arrow -->
+  <g stroke="#7a201a" stroke-width="2.2" fill="none" stroke-linecap="round" stroke-linejoin="round">
+    <line x1="243.58" y1="26.0" x2="261.58" y2="26.0"/>
+    <polyline points="254.98,21.2 261.58,26.0 254.98,30.8"/>
+  </g>
 </svg>