fix(firebase): rethrow CancellationException before wrapping in FetchException

Removing the RuntimeException catch in the previous commit inadvertently
caused CancellationException (a RuntimeException subclass) to be swallowed
and wrapped in FetchException, breaking structured concurrency.

Also restore pull_request trigger in docs.yml — publish-docs is already
gated with `if: github.event_name == 'push'` so docs are validated on PRs
but not published.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: kirich1409

.github/workflows/docs.yml

@@ -4,6 +4,9 @@ on:
   push:
     branches:
       - main
+  pull_request:
+    branches:
+      - main
     tags:
       - "v[0-9]+.[0-9]+.[0-9]+"
       - "v[0-9]+.[0-9]+.[0-9]+-*"

providers/firebase/src/main/kotlin/dev/androidbroadcast/featured/firebase/FirebaseConfigValueProvider.kt

@@ -5,6 +5,7 @@ import com.google.firebase.remoteconfig.FirebaseRemoteConfigValue
 import dev.androidbroadcast.featured.ConfigParam
 import dev.androidbroadcast.featured.ConfigValue
 import dev.androidbroadcast.featured.RemoteConfigValueProvider
+import kotlinx.coroutines.CancellationException
 import kotlinx.coroutines.tasks.await
 import kotlin.reflect.KClass
 
@@ -98,6 +99,8 @@ public class FirebaseConfigValueProvider(
 
         try {
             task.await()
+        } catch (e: CancellationException) {
+            throw e
         } catch (e: Exception) {
             throw FetchException("Firebase Remote Config fetch failed", e)
         }