+ Algae 3: parser, dual-mode evaluator, debugger REPL, differential tests

Port of ../algae3 (the Algae2 revival) into the SWObjects family:

- lib/Algae3Parser.ypp + Algae3Scanner.lpp + Algae3Parser.bnf: house-style
  bison-C++/flex (yacker rule names), conflict-free; builds the a3:: AST
  (lib/Algae3.hpp) over SWObjects terms/triples/expressions instead of the
  reference parser's S-expression strings. bin/algae3 evaluates, dumps the
  mode-named action algebra (--algebra), and hosts the debugger (--debug).

- lib/Algae3.cpp: the action pipeline (load with the merge/standardize-apart
  contract of sparql-to-algae3.md section 1, ask, test, assert, fwrule-to-
  fixpoint, let, bindings, collect with by-grouping / count(distinct) /
  group_concat(x, sep) / order/limit/offset, standalone {expr} as HAVING),
  per-row proof sets (munion pools them), and both evaluation modes:
  top-down correlated ./~/!/scope-lateral vs bottom-up Join/LeftJoin/Minus
  with unit-result-set isolation of connective operands and scopes.
  Flagged interpretations (file header): set-level orelse; |! as strict
  antijoin vs !'s SPARQL-Minus domain-disjoint vacuity.

- Debugger: step/where/print/bindings/watch/try/mode/break/run/reset;
  `try ( pattern )` speculatively counts extended/dropped rows under the
  current mode and discards; `mode bottomup` mid-session replays the
  remaining pipeline under SPARQL algebra.

- tests/Algae3: datasets for every manifesty.yaml entry, vendored .a3 with
  local loads, golden results, and differential mode tests: everything
  agrees across modes except the two documented divergences -
  nested-optional ({v=1,w=9,u=7} vs {v=1,w=9}) and negation-scoped, where
  the isolated union branch's naive MINUS cannot discriminate group members
  without a bound ?component and removes both neg conjuncts. The whole DNF
  rule-engine example (three nested aggregation layers, universal
  quantification by counting) evaluates correctly top-down.

All 22 ctest suites pass.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: Eric Prud'hommeaux

CMakeLists.txt

@@ -140,7 +140,7 @@ set(PARSER_GEN_DIR ${CMAKE_CURRENT_BINARY_DIR}/parsers)
 file(MAKE_DIRECTORY ${PARSER_GEN_DIR})
 
 set(SWOBJ_PARSER_STEMS
-    SPARQL SPARQLalgebra Turtle Trig MapSet SQL JSONresults ShExC)
+    SPARQL SPARQLalgebra Turtle Trig MapSet SQL JSONresults ShExC Algae3)
 
 set(SWOBJ_GENERATED_SOURCES "")
 foreach(stem IN LISTS SWOBJ_PARSER_STEMS)
@@ -167,6 +167,7 @@ add_library(SWObjects STATIC
   lib/ShExShapeMap.cpp
   lib/ShExManifest.cpp
   lib/ShExMap.cpp
+  lib/Algae3.cpp
   lib/SWObjects.cpp
   ${SWOBJ_GENERATED_SOURCES}
 )
@@ -230,7 +231,7 @@ target_precompile_headers(SWObjects PRIVATE lib/SWObjects.hpp)
 
 # The tools land in the source-tree bin/ directory (gitignored), as with the
 # old Makefile; the tests shell out to ../bin/sparql .
-foreach(tool sparql parseAndFree)
+foreach(tool sparql parseAndFree algae3)
   add_executable(${tool} bin/${tool}.cpp)
   target_link_libraries(${tool} PRIVATE SWObjects
     Boost::program_options Boost::filesystem)