feat(form-builder): retry history table + integration (WS-6)

Per-attempt retry history (timestamp, user, outcome, exception detail
if failed) replaces the counter-only retry_count tracking.

Changes:

- New `form_submission_action_failure_retry_attempts` table (cascade on
  parent delete, nullOnDelete on user). Explicit short FK names
  (`fsafra_failure_fk`, `fsafra_user_fk`) — auto-generated names exceed
  MySQL's 64-char identifier limit.
- New FormSubmissionActionFailureRetryAttempt model + factory +
  succeeded() state.
- Parent FormSubmissionActionFailure gets retryAttempts() HasMany
  relation (latest('attempted_at')).
- New FormFailureRetryService centralises the retry-flow logic. Both
  the API controller and the artisan command delegate to it. Service
  writes a retry_attempt record per attempt; parent's retry_count
  stays as denormalised cache for index-view performance.
- Successful retry: attempt(succeeded) + parent.retry_count++ +
  parent.resolved_at + parent.resolved_by_user_id + parent.resolved_note
  ("Geslaagde retry door {actor.name}" or "Geslaagde retry
  (geautomatiseerd)" for command-line invocation without an actor).
- Failed retry: attempt(failed) with NEW exception details +
  parent.retry_count++. Parent's exception_class/_message stay
  audit-immutable — they represent the FIRST failure.
- canBeRetried() now correctly checks both resolved_at AND
  dismissed_at (sessie 2's open question Q2 closure).
- New FailureNotRetriableException (controller → 422) and
  ParentSubmissionGoneException (controller → 410) for cleaner
  flow control.

12 new tests:
- FormSubmissionActionFailureRetryAttemptTest (5 unit tests)
- RetryFlowProducesRetryAttemptsTest (7 integration tests covering
  succeeded path, failed path, resolved/dismissed blocking,
  multiple-retries chronological ordering, canBeRetried truth tables)

Pre-existing tests touched:
- FormSubmissionActionFailureTest::test_can_be_retried_only_for_open_state
  — updated to reflect Q2 closure (resolved now blocks too).
- Ws6FoundationMigrationTest::test_down_methods_clean_up_columns_and_table
  — child table must drop before parent (FK constraint).
- 5 backfill test step-counts bumped +1 (new migration sits at top).

SCHEMA.md → v2.9. Schema dump regenerated.

Refs: RFC-WS-6.md §3 Q5 addendum, sessie 2 Q2

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

api/database/migrations/2026_04_28_180000_create_form_submission_action_failure_retry_attempts_table.php

@@ -0,0 +1,58 @@
+<?php
+
+declare(strict_types=1);
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+/**
+ * RFC-WS-6.md §3 (Q5) addendum — per-attempt retry history.
+ *
+ * Sessie 1's form_submission_action_failures.retry_count is a counter
+ * only. Sessie 3c adds per-attempt records (timestamp, user, outcome,
+ * exception details if failed) so the admin UI can show retry history.
+ *
+ * retry_count on the parent stays as denormalized cache for index-view
+ * performance. Service layer keeps both in sync per retry.
+ *
+ * No backfill: pre-launch the table is empty and dev seeders re-seed
+ * every iteration.
+ *
+ * Note on constraint names: the table name is 43 chars long; auto-generated
+ * FK constraint names (`{table}_{column}_foreign`) exceed MySQL's 64-char
+ * identifier limit. Each FK uses an explicit short name below.
+ */
+return new class extends Migration
+{
+    public function up(): void
+    {
+        Schema::create('form_submission_action_failure_retry_attempts', function (Blueprint $table): void {
+            $table->ulid('id')->primary();
+            $table->ulid('form_submission_action_failure_id');
+            $table->timestamp('attempted_at');
+            $table->ulid('attempted_by_user_id')->nullable();
+            $table->enum('outcome', ['succeeded', 'failed']);
+            $table->string('exception_class', 255)->nullable();
+            $table->text('exception_message')->nullable();
+            $table->timestamps();
+
+            $table->foreign('form_submission_action_failure_id', 'fsafra_failure_fk')
+                ->references('id')
+                ->on('form_submission_action_failures')
+                ->cascadeOnDelete();
+
+            $table->foreign('attempted_by_user_id', 'fsafra_user_fk')
+                ->references('id')
+                ->on('users')
+                ->nullOnDelete();
+
+            $table->index(['form_submission_action_failure_id', 'attempted_at'], 'fsafra_failure_attempt_idx');
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::dropIfExists('form_submission_action_failure_retry_attempts');
+    }
+};