Normalizes search_many/2 entry tuples and shared runtime options.
Shared and per-entry keyword options merge with per-key right bias: when both
sides define the same top-level key, the entry value wins (same as
Keyword.merge/3 with a conflict function returning the entry side).
Summary
Functions
Normalizes entries with shared_opts, returning {:ok, list} of
{schema, text, merged_opts} in declaration order.