Allow beta-typed Modrinth builds for EasyAuth (easyauth:beta)

EasyAuth publishes its 26.x builds as beta on Modrinth, and the itzg
resolver only accepts release-typed versions by default, so the mc
container failed to start. Pin easyauth:beta in the default mod list and
teach the panel's mod manager to compare entries by base slug so version
qualifiers don't break protected/duplicate checks.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.env.example

@@ -24,7 +24,9 @@ MC_SEED=
 
 # Server-side mods (Modrinth project slugs, comma-separated).
 # Auto-resolved to the newest compatible release on every container start.
-MODRINTH_PROJECTS=fabric-api,easyauth,spark,lithium,ferrite-core
+# Append ":beta" to allow beta-typed builds for a project (EasyAuth ships
+# its 26.x builds as beta on Modrinth).
+MODRINTH_PROJECTS=fabric-api,easyauth:beta,spark,lithium,ferrite-core
 # To run a full modpack instead, set its Modrinth slug (e.g. adrenaline)
 # and see docs/mods-and-modpacks.md before enabling.
 MODRINTH_MODPACK=