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/Exceptions/TenantScopeResolutionException.php

@@ -8,10 +8,10 @@ use RuntimeException;
 
 /**
  * Raised when OrganisationScope's FK-chain resolver walks past its max
- * hop limit (3 hops) without reaching a column-based strategy, or when
- * a chain's intermediate model returns an invalid tenantScopeStrategy()
- * shape. Indicates a misconfigured model — fail loud rather than silently
- * leak queries across tenants.
+ * hop limit (5 hops — raised from 3 in WS-5c) without reaching a
+ * column-based strategy, or when a chain's intermediate model returns
+ * an invalid tenantScopeStrategy() shape. Indicates a misconfigured
+ * model — fail loud rather than silently leak queries across tenants.
  */
 final class TenantScopeResolutionException extends RuntimeException
 {