feat(docs): add OpenRouter AI provider and improved tag color algorithm

apps/docs/blume.config.ts

@@ -1,4 +1,5 @@
 import { defineConfig } from "blume";
+import { openrouter } from "blume/ai";
 import type { StandardSchema } from "blume/core/standard-schema.ts";
 import { custom, filesystem } from "blume/sources";
 import { githubReleasesSource } from "blume/sources/github-releases.ts";
@@ -134,6 +135,18 @@ export default defineConfig({
     structuredData: true,
     x: { handle: "@prdlk" },
   },
+  // The assistant's `/api/ask` route runs on demand and reads
+  // OPENROUTER_API_KEY at request time (`getSecret`), so it needs a server
+  // runtime holding that secret — a static host cannot answer it.
+  ai: {
+    assistant: {
+      enabled: true,
+      provider: openrouter({
+        model: "qwen/qwen3.8-27b:free",
+        reasoning: "none",
+      }),
+    },
+  },
   agents: {
     llmsTxt: true,
     mcp: { enabled: false },