fix: drop better-auth peer to fix npm eresolve (#309)

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

Author: HugoRCD

.changeset/npm-drop-better-auth-peer.md

@@ -0,0 +1,5 @@
+---
+"evlog": patch
+---
+
+Remove `better-auth` from `peerDependencies`. Optional peers still led npm to resolve Better Auth’s peer graph (including `@sveltejs/kit` / Vite), causing `ERESOLVE` for apps that do not use Better Auth ([#299](https://github.com/HugoRCD/evlog/issues/299)). Users of `evlog/better-auth` should keep `better-auth` as a direct dependency (see docs).

apps/docs/content/2.logging/6.better-auth.md

@@ -18,6 +18,10 @@ links:
 
 `evlog/better-auth` turns anonymous wide events into identified ones. Every request automatically includes who made it — no manual `log.set({ user })` needed.
 
+## Prerequisites
+
+Use [Better Auth](https://better-auth.com/) as a **direct dependency** in your app (`npm i better-auth`, `pnpm add better-auth`, `bun add better-auth`, etc.). `evlog` does not bundle Better Auth. The integration is tested against Better Auth `>=1.6.9` (same major as [the playground](https://github.com/HugoRCD/evlog/tree/main/apps/playground)).
+
 ::code-collapse
 
 ```txt [Prompt]

bun.lock

@@ -364,8 +364,7 @@
     "react-router": ">=7.14.2",
     "vite": "^7.0.0 || ^8.0.0",
     "ai": ">=6.0.168",
-    "@tanstack/start-client-core": "^1.167.20",
-    "better-auth": ">=1.6.9"
+    "@tanstack/start-client-core": "^1.167.20"
   },
   "peerDependenciesMeta": {
     "@nuxt/kit": {
@@ -415,9 +414,6 @@
     },
     "@tanstack/start-client-core": {
       "optional": true
-    },
-    "better-auth": {
-      "optional": true
     }
   }
 }