feat(form-builder): form_field_conditional_logic_{groups,conditions} tables + OrganisationScope cap raise to 5

WS-5c commit 1 of 4 — relational infrastructure for the conditional-
logic tree that replaces form_fields.conditional_logic JSON (ARCH-
FORM-BUILDER §8; addendum Q3 WS-5c).

Tables: groups (nesting via parent_group_id) + conditions (leaves,
value JSON nullable for empty/not_empty). Simple FK to form_fields —
addendum Q3 explicitly excludes form_field_library from conditional_
logic scope, so no polymorphic morph here.

OrganisationScope cap raised 3 → 5 hops. The conditions chain is
4 hops (condition → group → field → schema → organisation_id column)
and the new cap gives headroom for future deeper trees without
denormalising form_field_id onto conditions.

Cascade observer (FormFieldChildTablesCascadeObserver) extended to
physically delete the new groups table on FormField delete (hard or
soft). Conditions cascade automatically via the group_id FK on the
groups table.

Factories: FormFieldConditionalLogicGroupFactory, FormFieldConditional
LogicConditionFactory, and FormFieldFactory::withConditionalLogic($tree)
for concise test fixtures.

Tests: 16 new under tests/Feature/FormBuilder/ConditionalLogic/
(relation, scope, cascade, enum catalogue). 3 new scope-cap tests in
ScopeLeakageTest verify 4/5-hop chains pass and 6-hop throws. Hardcoded
rollback step counts in WS-5a/b migration tests bumped for the 2 new
WS-5c migrations. Baseline 1104 → 1122 green (2988 → 3032 assertions).

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

api/app/Enums/FormBuilder/FormFieldConditionalLogicConditionOperator.php

@@ -0,0 +1,44 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Enums\FormBuilder;
+
+/**
+ * Comparison operator catalogue for relational conditional-logic leaves
+ * (ARCH-FORM-BUILDER §8, Phase A seed-scan confirmed catalogue parity
+ * with the frontend evaluator in
+ * `packages/form-schema/src/composables/useConditionalLogic.ts`).
+ *
+ * `Empty` / `NotEmpty` do not read the `value` column — the DB stores
+ * null for those rows. The service layer enforces this contract.
+ */
+enum FormFieldConditionalLogicConditionOperator: string
+{
+    case Equals = 'equals';
+    case NotEquals = 'not_equals';
+    case Contains = 'contains';
+    case NotContains = 'not_contains';
+    case In = 'in';
+    case NotIn = 'not_in';
+    case GreaterThan = 'greater_than';
+    case LessThan = 'less_than';
+    case Empty = 'empty';
+    case NotEmpty = 'not_empty';
+
+    /**
+     * Operators that do NOT consume `value`. Used by the service-layer
+     * shape validator and by the backfill migration's null-coercion.
+     *
+     * @return array<int, self>
+     */
+    public static function valuelessCases(): array
+    {
+        return [self::Empty, self::NotEmpty];
+    }
+
+    public function isValueless(): bool
+    {
+        return in_array($this, self::valuelessCases(), true);
+    }
+}

api/app/Enums/FormBuilder/FormFieldConditionalLogicGroupOperator.php

@@ -0,0 +1,17 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Enums\FormBuilder;
+
+/**
+ * Boolean group operator for relational conditional logic
+ * (ARCH-FORM-BUILDER §8). `All` ≡ AND, `Any` ≡ OR. Groups nest
+ * arbitrarily; Phase A seed-scan observed nesting depth ≤ 2 in the
+ * wild, well inside the OrganisationScope FK-chain cap.
+ */
+enum FormFieldConditionalLogicGroupOperator: string
+{
+    case All = 'all';
+    case Any = 'any';
+}