fix(flows): fix OpenAPI spec generation for FlowController endpoints

The Micronaut OpenAPI annotation processor was silently skipping all
FlowController endpoints mapped to `{namespace}/{id}` (GET, PUT, DELETE)
because processing `FlowWithSource` → `Flow`/`Task` → `AbstractRetry`
triggered a `PostponeToNextRoundException` on the concrete retry subtypes
(Constant, Exponential, Random). This exception occurs because the Micronaut
constraint validators on those subtypes are processed in the same annotation
processing round, making their metadata unavailable when the OpenAPI processor
tries to introspect them.

Fix: annotate the `retry` field in both `Flow` and `Task` with
`@Schema(implementation = Object.class)` to prevent the processor from
following the `@JsonSubTypes` chain on `AbstractRetry`. Also add class-level
`@Schema` documentation to the concrete retry subtypes.

Author: AcevedoR

core/src/main/java/io/kestra/core/models/flows/Flow.java

@@ -103,6 +103,14 @@ public List<Task> getFinally() {
     @Valid
     List<Output> outputs;
 
+    // implementation = Object.class prevents the Micronaut OpenAPI annotation processor from following
+    // the @JsonSubTypes on AbstractRetry, which causes a PostponeToNextRoundException at compile time
+    // due to the Micronaut constraint validators on the concrete retry subtypes (Constant, Exponential, Random).
+    @Schema(
+        title = "Retry",
+        description = "Retry policy applied when the flow fails.",
+        implementation = Object.class
+    )
     @Valid
     AbstractRetry retry;
 

core/src/main/java/io/kestra/core/models/tasks/Task.java

@@ -18,6 +18,7 @@
 import io.kestra.core.runners.RunContext;
 import io.kestra.plugin.core.flow.WorkingDirectory;
 
+import io.swagger.v3.oas.annotations.media.Schema;
 import jakarta.annotation.Nullable;
 import jakarta.validation.Valid;
 import jakarta.validation.constraints.Size;
@@ -45,6 +46,10 @@ abstract public class Task implements TaskInterface {
     @PluginProperty(hidden = true, group = "advanced")
     private String description;
 
+    // implementation = Object.class prevents the Micronaut OpenAPI annotation processor from following
+    // the @JsonSubTypes on AbstractRetry, which causes a PostponeToNextRoundException at compile time
+    // due to the Micronaut constraint validators on the concrete retry subtypes (Constant, Exponential, Random).
+    @Schema(title = "Retry", description = "Retry policy applied when the task fails.", implementation = Object.class)
     @Valid
     @PluginProperty(hidden = true, group = "reliability")
     protected AbstractRetry retry;

core/src/main/java/io/kestra/core/models/tasks/retrys/Constant.java

@@ -8,6 +8,7 @@
 import io.kestra.core.validations.ConstantRetryValidation;
 
 import dev.failsafe.RetryPolicyBuilder;
+import io.swagger.v3.oas.annotations.media.Schema;
 import jakarta.validation.constraints.NotNull;
 import lombok.Builder;
 import lombok.Getter;
@@ -18,6 +19,7 @@
 @Getter
 @NoArgsConstructor
 @ConstantRetryValidation
+@Schema(title = "Constant retry", description = "Retry with a fixed delay between attempts.")
 public class Constant extends AbstractRetry {
     @NotNull
     @JsonInclude

core/src/main/java/io/kestra/core/models/tasks/retrys/Exponential.java

@@ -9,6 +9,7 @@
 import io.kestra.core.validations.ExponentialRetryValidation;
 
 import dev.failsafe.RetryPolicyBuilder;
+import io.swagger.v3.oas.annotations.media.Schema;
 import jakarta.validation.constraints.NotNull;
 import lombok.Builder;
 import lombok.Getter;
@@ -19,6 +20,7 @@
 @Getter
 @NoArgsConstructor
 @ExponentialRetryValidation
+@Schema(title = "Exponential retry", description = "Retry with exponentially increasing delays between attempts.")
 public class Exponential extends AbstractRetry {
     @NotNull
     @JsonInclude

core/src/main/java/io/kestra/core/models/tasks/retrys/Random.java

@@ -9,6 +9,7 @@
 import io.kestra.core.validations.RandomRetryValidation;
 
 import dev.failsafe.RetryPolicyBuilder;
+import io.swagger.v3.oas.annotations.media.Schema;
 import jakarta.validation.constraints.NotNull;
 import lombok.Builder;
 import lombok.Getter;
@@ -19,6 +20,7 @@
 @Getter
 @NoArgsConstructor
 @RandomRetryValidation
+@Schema(title = "Random retry", description = "Retry with a random delay within a configurable range between attempts.")
 public class Random extends AbstractRetry {
     @NotNull
     @JsonInclude