Add default no-op implementations for ViewLogsUrlProvider and ViewDashboardUrlProvider

PR #537 introduced ViewDashboardAction and ViewLogsAction which require
ViewDashboardUrlProvider and ViewLogsUrlProvider to be bound in the Guice
injector. However, these bindings were not provided in BackfilaServiceModule,
causing injection failures in downstream services like cash-server.

This change adds default no-op implementations that return '#' as placeholder
URLs. These satisfy Guice's dependency requirements and allow the service to
start successfully. Deployments can override these bindings with real
implementations that link to their actual logging and monitoring infrastructure.

Fixes cash-server InjectorTest failures.

Author: jeffhwang-sq

service/src/main/kotlin/app/cash/backfila/service/BackfilaServiceModule.kt

@@ -9,8 +9,11 @@ import app.cash.backfila.client.GrpcCallbackConnectorProvider
 import app.cash.backfila.client.HttpCallbackConnectorProvider
 import app.cash.backfila.dashboard.BackfilaDashboardModule
 import app.cash.backfila.dashboard.BackfilaWebActionsModule
+import app.cash.backfila.dashboard.ViewDashboardUrlProvider
+import app.cash.backfila.dashboard.ViewLogsUrlProvider
 import app.cash.backfila.service.listener.BackfilaListenerModule
 import app.cash.backfila.service.persistence.BackfilaPersistenceModule
+import app.cash.backfila.service.persistence.DbBackfillRun
 import app.cash.backfila.service.runner.BackfillRunnerLoggingSetupProvider
 import app.cash.backfila.service.runner.BackfillRunnerNoLoggingSetupProvider
 import app.cash.backfila.service.scheduler.ForBackfilaScheduler
@@ -23,6 +26,7 @@ import java.util.concurrent.Executors
 import javax.inject.Qualifier
 import javax.inject.Singleton
 import misk.config.ConfigModule
+import misk.hibernate.Session
 import misk.inject.KAbstractModule
 import misk.security.authz.AccessAnnotationEntry
 import misk.slack.SlackModule
@@ -68,6 +72,11 @@ class BackfilaServiceModule(
 
     bind<BackfillRunnerLoggingSetupProvider>().to(runnerLoggingSetupProvider)
 
+    // Provide default no-op implementations for URL providers
+    // Deployments should override these with real implementations
+    bind<ViewLogsUrlProvider>().to<NoOpViewLogsUrlProvider>()
+    bind<ViewDashboardUrlProvider>().to<NoOpViewDashboardUrlProvider>()
+
     if (config.slack != null) {
       install(SlackModule(config.slack))
     }
@@ -88,3 +97,25 @@ class BackfilaServiceModule(
     )
   }
 }
+
+/**
+ * Default no-op implementation for ViewLogsUrlProvider.
+ * Deployments should override this binding with a real implementation that provides
+ * links to their logging infrastructure.
+ */
+internal class NoOpViewLogsUrlProvider : ViewLogsUrlProvider {
+  override fun getUrl(session: Session, backfillRun: DbBackfillRun): String {
+    return "#" // Return a no-op URL
+  }
+}
+
+/**
+ * Default no-op implementation for ViewDashboardUrlProvider.
+ * Deployments should override this binding with a real implementation that provides
+ * links to their dashboard/monitoring infrastructure.
+ */
+internal class NoOpViewDashboardUrlProvider : ViewDashboardUrlProvider {
+  override fun getUrl(session: Session, backfillRun: DbBackfillRun): String {
+    return "#" // Return a no-op URL
+  }
+}