fix(gen-shacl): correct rule-converter path parity, combined bounds, and SPARQL escaping

[jdsika]

Summary

Review-hardening pass over the rules → SHACL-SPARQL converters. Three latent
defects, each with regression tests that fail before the fix (re-verified
on this stack: running the new tests against the pre-fix generator source
yields 5 failures):

1. Induced-slot parity (silent false negative). _slot_uri and
   _resolve_enum_value_ref resolved the base slot, so a slot_usage
   override of slot_uri (or a narrowed enum range) made the SPARQL body
   query a property / enum IRI the data never uses, while sh:path used the
   induced IRI. The constraint then silently never fired. Both now resolve
   the induced slot for the class, matching the sh:path logic in the main
   slot loop. Affected code originates in feat(gen-shacl): generate sh:sparql constraints from LinkML rules #11 (framework) — this fix must be
   folded into the framework commit when submitting upstream.

2. Combined operators (silent under-constraint / false positives). A
   single precondition or member condition dispatched on the first matching
   operator, so a bounded range {minimum_value: X, maximum_value: Y} dropped
   the lower bound. A shared _scalar_filters helper now emits every
   recognised operator (and still returns None — skip, never mis-translate —
   when none is recognised). Affected code originates in the compositional
   fallback (base PR of this one).

3. SPARQL string escaping (invalid / injectable output). An
   equals_string or permissible-value name containing a ", \, or newline
   produced unparseable SPARQL. New _sparql_string_literal escapes per
   SPARQL 1.1 §19.7.
   Affects every converter that renders string terms (framework,
   presence-implies-value, fallback).

Stack position

Base branch: feat/shaclgen-compositional-rule-fallback — only the hardening
delta shows in the diff.

main
└─ feat/shaclgen-rules-sparql                      #11 (green)
   └─ feat/shaclgen-presence-implies-value-stacked   (PR: presence-implies-value)
      └─ feat/shaclgen-compositional-rule-fallback   (PR: fallback M1–M5)
         └─ fix/shaclgen-rule-converter-hardening   ← this PR

Kept as a separate commit (rather than folded into the feature branches) so
the defects, their failure modes, and the regression tests remain visible to
review. When upstreaming to linkml/linkml, fold each fix into the submission
that introduces the affected code, as noted per defect above.

Provenance

Cherry-pick of e263def7 from feat/shacl-rule-converters (#18), where the
full CI matrix is green.

How was this tested?

• tests/linkml/test_generators/test_shaclgen.py on this branch:
  106 passed (base suites + 6 regression tests: structural, prepareQuery
  syntax, and pyshacl end-to-end — including the below-threshold case proving
  the lower bound is enforced, and an end-to-end proof that a
  slot_usage-overridden constraint actually fires).
• Negative control: with this branch's tests but the pre-fix generator
  source, the regression tests fail (5 failures) — the tests bite.
• ruff check and ruff format --check clean on both changed files.

Areas of uncertainty

• The audit of this stack showed the parity fix stops one hop short (inner slots of range_expression / has_member conditions) and that value_presence: ABSENT combined with another operator was still translated; both are fixed with regression tests in the stacked fix(gen-shacl): enforce operator exactness, nested-slot parity, numeric bounds #22.
• Alias-form rule keys (a rule key written my_slot for a slot named my slot) silently fell back to the default-prefix CURIE — also fixed in the stacked fix(gen-shacl): enforce operator exactness, nested-slot parity, numeric bounds #22 (audit C4).

Checklist

• My code follows the contributor guidelines
• I have added tests that prove my fix/feature works
• Existing tests pass locally with my changes

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[jdsika]

Adversarial audit of the hardening fixes (probed at this tip)

Fix claims that held under attack: top-level induced-slot parity (sh:path and SPARQL body byte-agree for slot_usage-overridden slot_uri, incl. attributes — class_induced_slots never mangles names, so the element_by_schema_map membership test matches the main slot loop); combined {minimum_value, maximum_value} emits both bounds; quote/backslash/newline escaping produces parseable queries (\b/\f are legal raw in SPARQL STRING_LITERAL2, so leaving them unescaped is fine).

C1 — real bug: the parity fix stops one hop short, and the new class_slots check regresses the name-collision case.
Nested conditions (range_expression, has_member members) still resolve the inner slot via _slot_uri(sv, inner_name, cls) with the outer class:

• Without collision: a child class narrowing an inner slot's slot_uri via its own slot_usage gets sh:path ≠ SPARQL body (the claimed defect class, one hop deeper).
• With collision (regression): when the inner slot name also exists on the outer class with a different slot_usage URI, the new if slot_name in sv.class_slots(cls.name): induced_slot(...) makes the outer induced slot win. The pre-fix code (plain get_slot) emitted the correct child URI in this case; the post-fix code emits the parent's. For has_member the wrong predicate makes FILTER NOT EXISTS vacuously true → false positives on conforming data (demonstrated with pyshacl).
  Same family: _resolve_member_enum_ref uses non-induced sv.get_slot(container_slot_name), so container-slot range narrowing resolves the wrong enum. See also the matching finding on the base PR (fallback), where the fix belongs.

C2 — edge case: _scalar_filters drops value_presence: ABSENT when combined with another operator.
Pure ABSENT preconditions are correctly rejected (verified — no inverted-semantics constraint is emitted). But {value_presence: ABSENT, minimum_value: 5} translates as if the slot must be present with the bound — the opposite of the declared trigger. Only reachable via a self-contradictory condition, but it breaches this PR's own "skip, never mis-translate" contract. Fix: return None when value_presence is set to anything other than PRESENT (same hole in _member_conditions inner conditions).

C3 — real bug (pre-existing; this PR's new docstring mis-states it): _sparql_number passes non-numeric values raw.
The docstring added here claims LinkML parses minimum_value/maximum_value as int/float — the metamodel range is Anything. A YAML date bound 2020-01-01 emits FILTER ( ?pre0 >= 2020-01-01 ), which parses as the arithmetic expression 2020−01−01 = 2018 (silent false negative); "abc"/.nan produce unparseable sh:select that makes pyshacl raise on the entire shapes graph. Gate on real numerics and skip otherwise.

C4 — cosmetic: alias-form rule keys silently diverge. A rule key written my_slot for a slot named my slot misses class_slots/get_slot and falls back to default_prefix:my_slot while sh:path uses the overridden URI — a vacuous constraint with no warning. linkml-runtime's induced_slot normalizes aliases via slot_name_mappings(); here it diverges silently instead of skipping/warning.

Also verified: malformed meaning CURIEs fail loudly at generation (no injection path); remaining interpolation sites (rule description via rdflib.Literal, int-cast cardinalities, get_uri/expand_curie IRIs) are safe.

Suggest a follow-up commit on this stack for C1–C3 before upstreaming (C1's fix best lands where the nested emitters live, i.e. the fallback commit, when folding for upstream submission).

[jdsika]

The substantive audit findings above are resolved in #22 (fix/shaclgen-rule-converter-audit-findings, stacked on this series) — one commit, 19 regression tests, 18 of which fail on the pre-fix source. See the finding→fix table in the #22 description.