fix(gen-shacl): enforce operator exactness, nested-slot parity, numeric bounds

Resolve the adversarial-audit findings on the rule-converter stack. Every
fix carries regression tests; 18 of the 19 new tests fail on the pre-fix
source (the 19th locks in already-correct zero-member has_member
semantics that had no coverage).

- Operator exactness (audit A1/B2/C2): named patterns and the
  compositional fallback now require their conditions to set EXACTLY the
  operators they translate. A new _set_operator_fields helper enumerates
  the constraint-bearing fields actually set on a condition or class
  expression (metadata excluded; scalars never judged by truthiness, so
  minimum_value: 0 still counts). Previously a condition mixing a
  recognized operator with an unrecognized one (equals_string + pattern),
  expression-level any_of/all_of/none_of/exactly_one_of, co-set
  equals_string + equals_string_in, or value_presence: ABSENT combined
  with a bound was partially translated, silently dropping conjuncts and
  producing demonstrated false positives. All such rules are now skipped
  (skip, never mis-translate).

- Boolean-guard range gate (audit A2): the boolean-guard pattern only
  dispatches when the target slot's induced range is boolean. An
  equals_string "true" postcondition on a string-range slot previously
  hijacked the boolean comparison and flagged conforming data; it now
  dispatches to presence-implies-value, which compares the string.

- Nested inner-slot parity (audit B1/C1): _member_conditions resolves the
  container slot in the induced context of the outer class, requires its
  range to be a class, and resolves inner slot URIs and enum values
  against that range class. Previously inner slots resolved against the
  OUTER class: a slot_usage slot_uri override on the member class made
  sh:path and the SPARQL body diverge (constraint silently never fired),
  and an inner slot name colliding with an outer slot_usage override
  queried a predicate members never carry, making has_member's FILTER NOT
  EXISTS vacuously true (false positives on conforming data). The
  _resolve_member_enum_ref special case is subsumed by passing the range
  class to _resolve_enum_value_ref.

- Numeric bound gate (audit B3/C3): _sparql_number returns None for
  anything but int / finite float (bool excluded), and callers skip the
  rule. The metamodel range of minimum_value/maximum_value is Anything:
  a string bound produced unparsable SPARQL that poisoned the entire
  shapes graph at validation time, and a YAML date parsed as arithmetic
  (2020-01-01 = 2018), silently never firing. Docstring corrected.

- elseconditions warning (audit B4): rules with an else branch now log a
  warning that only the forward direction is enforced, consistent with
  the bidirectional/open_world warnings.

- Test hygiene: the vacuous "<Manual> not in query" assertion now checks
  the full IRI form; new zero-member has_member end-to-end test.

Signed-off-by: Carlo van Driesten <carlo.van-driesten@vdl.digital>

Author: jdsika