feat(providers/logos): add logos for 5 new free providers

- public/providers/longcat.png — pink cat icon (generated)
- public/providers/pollinations.png — pixel bee icon (generated)
- public/providers/aimlapi.png — indigo neural network icon (generated)
- public/providers/cloudflare-ai.svg — Cloudflare official SVG (simpleicons.org)
- public/providers/scaleway.svg — Scaleway official SVG (simpleicons.org)

Icons serve at /providers/{id}.png (PNG fallback to SVG)

public/providers/cloudflare-ai.svg

@@ -0,0 +1 @@
+<svg role="img" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><title>Cloudflare</title><path d="M16.5088 16.8447c.1475-.5068.0908-.9707-.1553-1.3154-.2246-.3164-.6045-.499-1.0615-.5205l-8.6592-.1123a.1559.1559 0 0 1-.1333-.0713c-.0283-.042-.0351-.0986-.021-.1553.0278-.084.1123-.1484.2036-.1562l8.7359-.1123c1.0351-.0489 2.1601-.8868 2.5537-1.9136l.499-1.3013c.0215-.0561.0293-.1128.0147-.168-.5625-2.5463-2.835-4.4453-5.5499-4.4453-2.5039 0-4.6284 1.6177-5.3876 3.8614-.4927-.3658-1.1187-.5625-1.794-.499-1.2026.119-2.1665 1.083-2.2861 2.2856-.0283.31-.0069.6128.0635.894C1.5683 13.171 0 14.7754 0 16.752c0 .1748.0142.3515.0352.5273.0141.083.0844.1475.1689.1475h15.9814c.0909 0 .1758-.0645.2032-.1553l.12-.4268zm2.7568-5.5634c-.0771 0-.1611 0-.2383.0112-.0566 0-.1054.0415-.127.0976l-.3378 1.1744c-.1475.5068-.0918.9707.1543 1.3164.2256.3164.6055.498 1.0625.5195l1.8437.1133c.0557 0 .1055.0263.1329.0703.0283.043.0351.1074.0214.1562-.0283.084-.1132.1485-.204.1553l-1.921.1123c-1.041.0488-2.1582.8867-2.5527 1.914l-.1406.3585c-.0283.0713.0215.1416.0986.1416h6.5977c.0771 0 .1474-.0489.169-.126.1122-.4082.1757-.837.1757-1.2803 0-2.6025-2.125-4.727-4.7344-4.727"/></svg>

public/providers/scaleway.svg

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+<svg role="img" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><title>Scaleway</title><path d="M16.605 11.11v5.72a1.77 1.77 0 01-1.54 1.69h-4a1.43 1.43 0 01-1.31-1.22 1.09 1.09 0 010-.18 1.37 1.37 0 011.37-1.36h1.74a1 1 0 001-1v-3.62a1.4 1.4 0 011.18-1.39h.17a1.37 1.37 0 011.39 1.36zm-6.46 1.74V9.26a1 1 0 011-1h1.85a1.37 1.37 0 001.37-1.37 1 1 0 000-.17 1.45 1.45 0 00-1.41-1.2h-3.96a1.81 1.81 0 00-1.58 1.66v5.7a1.37 1.37 0 001.37 1.37h.21a1.4 1.4 0 001.15-1.4zm12-4.29V20a4.53 4.53 0 01-4.15 4h-7.58a8.57 8.57 0 01-8.56-8.57V4.54A4.54 4.54 0 016.395 0h7.18a8.56 8.56 0 018.56 8.56zm-2.74 0a5.83 5.83 0 00-5.82-5.82h-7.19a1.79 1.79 0 00-1.8 1.8v10.89a5.83 5.83 0 005.82 5.8h7.44a1.79 1.79 0 001.54-1.48z"/></svg>