feat: shared infrastructure for plan migration

Platform-side building blocks consumed by the billing plan-migration feature
(the feature itself lives in the billing repo):
- email custom-template engine (renderer, placeholders extractor) and
  EmailTemplateModel/EmailPlaceholderModel DTOs
- SchedulingManager cron scheduling and CurrentDateProvider local-date accessor
- plan-migration error codes (Message, I18n_en) + frontend error translations
- reusable UI: FullWidthTooltip, FormatedDateTooltip, optional table headers in
  PaginatedHateoasTable, HeaderBar custom buttons, validation + links additions
- e2e textarea helpers
- registration email greeting placeholder fix (username -> recipientName)

Author: dkrizan

backend/data/src/main/kotlin/io/tolgee/component/CurrentDateProvider.kt

@@ -16,6 +16,8 @@ import org.springframework.stereotype.Component
 import org.springframework.transaction.PlatformTransactionManager
 import java.sql.Timestamp
 import java.time.Duration
+import java.time.LocalDate
+import java.time.ZoneId.systemDefault
 import java.time.ZonedDateTime
 import java.time.format.DateTimeFormatter
 import java.time.temporal.TemporalAccessor
@@ -86,6 +88,11 @@ class CurrentDateProvider(
       return forcedDate ?: Date()
     }
 
+  val localDate: LocalDate
+    get() {
+      return date.toInstant().atZone(systemDefault()).toLocalDate()
+    }
+
   override fun getNow(): Optional<TemporalAccessor> {
     return Optional.of(date.toInstant())
   }

backend/data/src/main/kotlin/io/tolgee/component/SchedulingManager.kt

@@ -3,6 +3,7 @@ package io.tolgee.component
 import io.tolgee.util.Logging
 import io.tolgee.util.logger
 import jakarta.annotation.PreDestroy
+import org.springframework.scheduling.support.CronTrigger
 import org.springframework.stereotype.Component
 import java.time.Duration
 import java.util.UUID
@@ -46,6 +47,19 @@ class SchedulingManager(
     return id
   }
 
+  fun scheduleWithCron(
+    runnable: Runnable,
+    cron: String,
+  ): String {
+    val future = taskScheduler.schedule(runnable, CronTrigger(cron))
+    if (future == null) {
+      throw IllegalStateException("Future from scheduler was null")
+    }
+    val id = UUID.randomUUID().toString()
+    scheduledTasks[id] = future
+    return id
+  }
+
   @PreDestroy
   fun cancelAll() {
     Companion.cancelAll()

backend/data/src/main/kotlin/io/tolgee/component/email/customTemplate/EmailTemplateRenderer.kt

@@ -0,0 +1,31 @@
+package io.tolgee.component.email.customTemplate
+
+import io.tolgee.component.email.customTemplate.placeholder.EmailPlaceholdersExtractor
+import org.springframework.stereotype.Component
+import java.text.MessageFormat
+import java.util.Locale
+import kotlin.reflect.KClass
+
+@Component
+class EmailTemplateRenderer(
+  private val placeholderExtractor: EmailPlaceholdersExtractor,
+) {
+  fun render(
+    template: String,
+    variables: EmailTemplateVariables,
+  ): String {
+    @Suppress("UNCHECKED_CAST")
+    val entries =
+      placeholderExtractor.getEntries(
+        variables::class as KClass<EmailTemplateVariables>,
+      )
+
+    val parameters =
+      entries
+        .map { entry ->
+          entry.accessor(variables) ?: ""
+        }.toTypedArray()
+
+    return MessageFormat(template, Locale.ENGLISH).format(parameters)
+  }
+}

backend/data/src/main/kotlin/io/tolgee/component/email/customTemplate/EmailTemplateVariables.kt

@@ -0,0 +1,6 @@
+package io.tolgee.component.email.customTemplate
+
+/**
+ * Marker interface for classes that describe email template variables via [io.tolgee.component.email.customTemplate.placeholder.EmailPlaceholder] annotations.
+ */
+interface EmailTemplateVariables

backend/data/src/main/kotlin/io/tolgee/component/email/customTemplate/placeholder/EmailPlaceholder.kt

@@ -0,0 +1,10 @@
+package io.tolgee.component.email.customTemplate.placeholder
+
+@Target(AnnotationTarget.PROPERTY)
+@Retention(AnnotationRetention.RUNTIME)
+annotation class EmailPlaceholder(
+  val position: Int,
+  val placeholder: String,
+  val description: String,
+  val exampleValue: String,
+)

backend/data/src/main/kotlin/io/tolgee/component/email/customTemplate/placeholder/EmailPlaceholderDefinition.kt

@@ -0,0 +1,15 @@
+package io.tolgee.component.email.customTemplate.placeholder
+
+import io.tolgee.component.email.customTemplate.EmailTemplateVariables
+
+data class EmailPlaceholderDefinition(
+  val position: Int,
+  val placeholder: String,
+  val description: String,
+  val exampleValue: String,
+)
+
+data class EmailPlaceholderEntry<T : EmailTemplateVariables>(
+  val definition: EmailPlaceholderDefinition,
+  val accessor: (T) -> String?,
+)

backend/data/src/main/kotlin/io/tolgee/component/email/customTemplate/placeholder/EmailPlaceholdersExtractor.kt

@@ -0,0 +1,54 @@
+package io.tolgee.component.email.customTemplate.placeholder
+
+import io.tolgee.component.email.customTemplate.EmailTemplateVariables
+import io.tolgee.util.I18n
+import org.springframework.stereotype.Component
+import java.util.concurrent.ConcurrentHashMap
+import kotlin.collections.set
+import kotlin.reflect.KClass
+import kotlin.reflect.full.findAnnotation
+import kotlin.reflect.full.memberProperties
+
+@Component
+class EmailPlaceholdersExtractor(
+  private val i18n: I18n,
+) {
+  private val cache =
+    ConcurrentHashMap<KClass<*>, List<EmailPlaceholderEntry<*>>>()
+
+  fun <T : EmailTemplateVariables> getEntries(kClass: KClass<T>): List<EmailPlaceholderEntry<T>> {
+    val existing = cache[kClass]
+    if (existing != null) {
+      @Suppress("UNCHECKED_CAST")
+      return existing as List<EmailPlaceholderEntry<T>>
+    }
+
+    val extracted = extract(kClass)
+    cache[kClass] = extracted
+    return extracted
+  }
+
+  fun <T : EmailTemplateVariables> getDefinitions(kClass: KClass<T>): List<EmailPlaceholderDefinition> {
+    return getEntries(kClass).map { it.definition }
+  }
+
+  private fun <T : EmailTemplateVariables> extract(kClass: KClass<T>): List<EmailPlaceholderEntry<T>> {
+    return kClass.memberProperties
+      .mapNotNull { property ->
+        val annotation = property.findAnnotation<EmailPlaceholder>() ?: return@mapNotNull null
+
+        EmailPlaceholderEntry(
+          definition =
+            EmailPlaceholderDefinition(
+              position = annotation.position,
+              placeholder = annotation.placeholder,
+              description = i18n.translate(annotation.description),
+              exampleValue = annotation.exampleValue,
+            ),
+          accessor = { instance: T ->
+            property.get(instance)?.toString()
+          },
+        )
+      }.sortedBy { it.definition.position }
+  }
+}

backend/data/src/main/kotlin/io/tolgee/constants/Message.kt

@@ -347,6 +347,9 @@ enum class Message {
   TRANSLATION_EXCEEDS_CHAR_LIMIT,
   URL_NOT_VALID,
   QA_CHECKS_NOT_ENABLED,
+  PLAN_MIGRATION_NOT_FOUND,
+  PLAN_HAS_MIGRATIONS,
+  SOURCE_AND_TARGET_PLAN_MUST_BE_DIFFERENT,
   ;
 
   val code: String

backend/data/src/main/kotlin/io/tolgee/dtos/misc/EmailPlaceholderModel.kt

@@ -0,0 +1,7 @@
+package io.tolgee.dtos.misc
+
+data class EmailPlaceholderModel(
+  val placeholder: String,
+  val description: String,
+  val exampleValue: String,
+)

backend/data/src/main/kotlin/io/tolgee/dtos/misc/EmailTemplateModel.kt

@@ -0,0 +1,6 @@
+package io.tolgee.dtos.misc
+
+data class EmailTemplateModel(
+  val body: String,
+  val placeholders: List<EmailPlaceholderModel>,
+)