Exercise 2: Confirming Genuinely Unbounded Depth — Possible Solution
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SETUP — SIX REAL LEVELS
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  id: 1, slug: 'programming',              parent_id: NULL
  id: 2, slug: 'general-purpose-languages', parent_id: 1
  id: 3, slug: 'java',                      parent_id: 2
  id: 4, slug: 'fundamentals',              parent_id: 3
  id: 5, slug: 'chapter-1',                 parent_id: 4
  id: 6, slug: 'section-a',                 parent_id: 5

CALLING THE EXACT SAME UNCHANGED QUERY FROM EXERCISE 1
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await getBreadcrumb(pool, 6);

RESULT
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[
  { id: 1, depth: 5, ... },
  { id: 2, depth: 4, ... },
  { id: 3, depth: 3, ... },
  { id: 4, depth: 2, ... },
  { id: 5, depth: 1, ... },
  { id: 6, depth: 0, ... }
]

All six real ancestors are returned, correctly ordered, from the same
SQL string used in Exercise 1 for a three-level chain - no nesting
was added, no depth number was hard-coded anywhere in the query.

WHY THIS WORKS AS AN ANSWER
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It correctly builds a tree six levels deep - deeper than every prior
sibling course's own fixed nested-eager-load limit - and correctly
confirms the unchanged recursive CTE resolves the full chain with
zero code modifications, concrete proof of the chapter's own central
finding.