feat(providers): add Poolside provider (OpenAI-compatible)

Adds Poolside (inference.poolside.ai) as an API-key provider using the default OpenAI transport. Registers three Laguna models with reasoning capabilities (262K context, 32K max output).

open-sse/providers/capabilities.js

@@ -174,6 +174,12 @@ export const PROVIDER_CAPABILITIES = {
     "deepseek-v4-flash":  { vision: true, reasoning: true, thinkingFormat: "openai", thinkingCanDisable: false, contextWindow: 1000000, maxOutput: 50000 },
     "deepseek-v3-2-volc": { reasoning: true, thinkingFormat: "openai", thinkingCanDisable: false, contextWindow: 96000, maxOutput: 32000 },
   },
+  // Poolside Laguna — OpenAI-compatible, all reasoning-capable (262K context, 32K max output).
+  "poolside": {
+    "laguna-s-2.1":  { reasoning: true, thinkingFormat: "openai", contextWindow: 262000, maxOutput: 32000 },
+    "laguna-xs-2.1": { reasoning: true, thinkingFormat: "openai", contextWindow: 262000, maxOutput: 32000 },
+    "laguna-m.1":    { reasoning: true, thinkingFormat: "openai", contextWindow: 262000, maxOutput: 32000 },
+  },
 };
 
 /**

open-sse/providers/registry/index.js

@@ -115,6 +115,7 @@ import p112 from "./tencent.js";
 import p113 from "./morph.js";
 import p114 from "./devin-cli.js";
 // import p104 from "./windsurf.js";
+import p115 from "./poolside.js";
 
 export default [
   p0,
@@ -231,4 +232,5 @@ export default [
   p113,
   p114,
   // p104, // windsurf — hidden, no tool calling
+  p115,
 ];

open-sse/providers/registry/poolside.js

@@ -0,0 +1,31 @@
+export default {
+  id: "poolside",
+  priority: 60,
+  alias: "poolside",
+  aliases: [
+    "ps",
+  ],
+  uiAlias: "ps",
+  display: {
+    name: "Poolside",
+    icon: "water_drop",
+    color: "#0EA5E9",
+    textIcon: "PS",
+    website: "https://poolside.ai",
+    notice: {
+      apiKeyUrl: "https://platform.poolside.ai/api-keys",
+    },
+  },
+  category: "freeTier",
+  authType: "apikey",
+  authModes: ["apikey"],
+  transport: {
+    baseUrl: "https://inference.poolside.ai/v1/chat/completions",
+    validateUrl: "https://inference.poolside.ai/v1/models",
+  },
+  models: [
+    { id: "poolside/laguna-s-2.1", name: "Laguna S 2.1" },
+    { id: "poolside/laguna-xs-2.1", name: "Laguna XS 2.1" },
+    { id: "poolside/laguna-m.1", name: "Laguna M.1" },
+  ],
+};