fix(lucide-preact): add conditional exports map for ESM/CJS resolution (#4198)

Without an exports map, runtimes that follow the Node.js package resolution
spec (Node.js, Bun) ignore the non-standard 'module' field and fall back to
'main' (CJS), even when the importing code is pure ESM. Since 1.0.0, the
package uses useContext and useMemo from preact/hooks internally, making this
a runtime-breaking issue: the CJS build loads a separate preact/hooks instance
which crashes on every icon render with 'undefined is not an object'.

Fixes #4196

packages/lucide-preact/package.json

@@ -25,6 +25,13 @@
   "amdName": "lucide-preact",
   "main": "dist/cjs/lucide-preact.js",
   "module": "dist/esm/lucide-preact.js",
+  "exports": {
+    ".": {
+      "types": "./dist/lucide-preact.d.ts",
+      "import": "./dist/esm/lucide-preact.js",
+      "require": "./dist/cjs/lucide-preact.js"
+    }
+  },
   "typings": "dist/lucide-preact.d.ts",
   "files": [
     "dist"