feat: implement solver registry architecture core

.gitignore

@@ -573,8 +573,10 @@ bindings/python/licenses/
 # Local agent scratch space
 .opencode/
 
-# Hiding LLM plan
+# Local one-off plan notes (keep repo plans tracked)
 docs/plan*
+!docs/plans/
+!docs/plans/**/*.md
 
 #
 artifacts/

.sentrux/rules.toml

@@ -0,0 +1,302 @@
+# Target-state architectural rules for Arco.
+#
+# These rules describe ARCHITECTURE_REFACTOR_PLAN.md, not the current
+# transitional workspace. A violation is migration debt unless the architecture
+# plan changes first.
+#
+# Layer order convention:
+#   order = 0 is the most foundational layer.
+#   Lower-order layers may depend on higher-order layers (Sentrux checks from low to high).
+
+[constraints]
+max_cycles = 0
+max_coupling = "C"
+max_cc = 25
+no_god_files = false
+
+# ---------------------------------------------------------------------------
+# Target layers
+# ---------------------------------------------------------------------------
+
+[[layers]]
+name = "primitive_model"
+paths = ["crates/arco-model/src/**"]
+order = 5
+
+[[layers]]
+name = "diagnostics"
+paths = ["crates/arco-diagnostics/src/**"]
+order = 5
+
+[[layers]]
+name = "solver_primitives"
+paths = ["crates/arco-solver/src/**"]
+order = 5
+
+[[layers]]
+name = "support_tooling"
+paths = ["crates/arco-tools/src/**"]
+order = 5
+
+[[layers]]
+name = "runtime_execution"
+paths = ["crates/arco-runtime/src/**"]
+order = 4
+
+[[layers]]
+name = "authoring_surfaces"
+paths = [
+  "crates/arco-kdl/src/**",
+  "crates/arco-json/src/**",
+  "crates/arco-yaml/src/**",
+]
+order = 4
+
+[[layers]]
+name = "validation"
+paths = ["crates/arco-validate/src/**"]
+order = 4
+
+[[layers]]
+name = "format_primitives"
+paths = [
+  "crates/arco-format/src/**",
+]
+order = 5
+
+[[layers]]
+name = "concrete_formats"
+paths = [
+  "crates/arco-lp/src/**",
+  "crates/arco-mps/src/**",
+  "crates/arco-nl/src/**",
+]
+order = 6
+
+[[layers]]
+name = "solver_adapters"
+paths = [
+  "crates/arco-highs/src/**",
+  "crates/arco-ipopt/src/**",
+  "crates/arco-xpress/src/**",
+  "crates/arco-scip/src/**",
+]
+order = 3
+
+
+[[layers]]
+name = "operations_adapter"
+paths = ["crates/arco-ops/src/**"]
+order = 2
+
+[[layers]]
+name = "block_composition"
+paths = ["crates/arco-blocks/src/**"]
+order = 1
+
+[[layers]]
+name = "interaction_surfaces"
+paths = [
+  "crates/arco-cli/src/**",
+  "bindings/python/src/**",
+]
+order = 0
+
+# ---------------------------------------------------------------------------
+# Interaction surfaces: use arco-ops only among Arco crates.
+# ---------------------------------------------------------------------------
+
+[[boundaries]]
+from = "crates/arco-cli/src/**"
+to = "crates/arco-model/src/**"
+reason = "CLI must use arco-ops instead of primitive model APIs directly"
+
+[[boundaries]]
+from = "crates/arco-cli/src/**"
+to = "crates/arco-blocks/src/**"
+reason = "CLI must consume block composition through arco-ops adapters"
+
+[[boundaries]]
+from = "crates/arco-cli/src/**"
+to = "crates/arco-kdl/src/**"
+reason = "CLI must use arco-ops instead of authoring surfaces directly"
+
+[[boundaries]]
+from = "crates/arco-cli/src/**"
+to = "crates/arco-validate/src/**"
+reason = "CLI must use arco-ops instead of validation directly"
+
+[[boundaries]]
+from = "crates/arco-cli/src/**"
+to = "crates/arco-format/src/**"
+reason = "CLI must use arco-ops instead of format primitives directly"
+
+[[boundaries]]
+from = "crates/arco-cli/src/**"
+to = "crates/arco-solver/src/**"
+reason = "CLI must use arco-ops instead of solver primitives directly"
+
+[[boundaries]]
+from = "crates/arco-cli/src/**"
+to = "crates/arco-runtime/src/**"
+reason = "CLI must use arco-ops instead of runtime execution directly"
+
+[[boundaries]]
+from = "bindings/python/src/**"
+to = "crates/arco-kdl/src/**"
+reason = "Python bindings must use arco-ops instead of authoring surfaces directly"
+
+[[boundaries]]
+from = "bindings/python/src/**"
+to = "crates/arco-validate/src/**"
+reason = "Python bindings must use arco-ops instead of validation directly"
+
+[[boundaries]]
+from = "bindings/python/src/**"
+to = "crates/arco-format/src/**"
+reason = "Python bindings must use arco-ops instead of format primitives directly"
+
+[[boundaries]]
+from = "bindings/python/src/**"
+to = "crates/arco-solver/src/**"
+reason = "Python bindings must use arco-ops instead of solver primitives directly"
+
+[[boundaries]]
+from = "bindings/python/src/**"
+to = "crates/arco-runtime/src/**"
+reason = "Python bindings must use arco-ops instead of runtime execution directly"
+
+[[boundaries]]
+from = "bindings/python/src/**"
+to = "crates/arco-highs/src/**"
+reason = "Python bindings must not couple directly to solver adapters"
+
+[[boundaries]]
+from = "bindings/python/src/**"
+to = "crates/arco-ipopt/src/**"
+reason = "Python bindings must not couple directly to solver adapters"
+
+[[boundaries]]
+from = "bindings/python/src/**"
+to = "crates/arco-xpress/src/**"
+reason = "Python bindings must not couple directly to solver adapters"
+
+[[boundaries]]
+from = "bindings/python/src/**"
+to = "crates/arco-scip/src/**"
+reason = "Python bindings must not couple directly to solver adapters"
+
+[[boundaries]]
+from = "crates/arco-kdl/src/**"
+to = "crates/arco-solver/src/**"
+reason = "KDL must stay solver-policy-neutral"
+
+[[boundaries]]
+from = "crates/arco-kdl/src/**"
+to = "crates/arco-runtime/src/**"
+reason = "KDL must not own runtime execution mechanics"
+
+[[boundaries]]
+from = "crates/arco-kdl/src/**"
+to = "crates/arco-format/src/**"
+reason = "KDL must not own format/export behavior"
+
+[[boundaries]]
+from = "crates/arco-kdl/src/**"
+to = "crates/arco-highs/src/**"
+reason = "KDL must not couple to concrete solver adapters"
+
+[[boundaries]]
+from = "crates/arco-kdl/src/**"
+to = "crates/arco-ipopt/src/**"
+reason = "KDL must not couple to concrete solver adapters"
+
+[[boundaries]]
+from = "crates/arco-kdl/src/**"
+to = "crates/arco-xpress/src/**"
+reason = "KDL must not couple to concrete solver adapters"
+
+[[boundaries]]
+from = "crates/arco-kdl/src/**"
+to = "crates/arco-scip/src/**"
+reason = "KDL must not couple to concrete solver adapters"
+
+[[boundaries]]
+from = "crates/arco-validate/src/**"
+to = "crates/arco-kdl/src/**"
+reason = "Validation must run over primitive model views, not KDL internals"
+
+[[boundaries]]
+from = "crates/arco-format/src/**"
+to = "crates/arco-kdl/src/**"
+reason = "Format primitives must not depend on authoring-surface internals"
+
+[[boundaries]]
+from = "crates/arco-format/src/**"
+to = "crates/arco-solver/src/**"
+reason = "Format primitives/concrete formats must not own solver selection policy"
+
+[[boundaries]]
+from = "crates/arco-solver/src/**"
+to = "crates/arco-kdl/src/**"
+reason = "Solver primitives must stay authoring-surface neutral"
+
+[[boundaries]]
+from = "crates/arco-solver/src/**"
+to = "crates/arco-highs/src/**"
+reason = "Solver primitives must stay adapter-neutral"
+
+[[boundaries]]
+from = "crates/arco-solver/src/**"
+to = "crates/arco-ipopt/src/**"
+reason = "Solver primitives must stay adapter-neutral"
+
+[[boundaries]]
+from = "crates/arco-solver/src/**"
+to = "crates/arco-xpress/src/**"
+reason = "Solver primitives must stay adapter-neutral"
+
+[[boundaries]]
+from = "crates/arco-solver/src/**"
+to = "crates/arco-scip/src/**"
+reason = "Solver primitives must stay adapter-neutral"
+
+[[boundaries]]
+from = "crates/arco-ops/src/**"
+to = "crates/arco-highs/src/**"
+reason = "arco-ops should use solver primitives instead of concrete adapters directly"
+
+[[boundaries]]
+from = "crates/arco-ops/src/**"
+to = "crates/arco-ipopt/src/**"
+reason = "arco-ops should use solver primitives instead of concrete adapters directly"
+
+[[boundaries]]
+from = "crates/arco-ops/src/**"
+to = "crates/arco-xpress/src/**"
+reason = "arco-ops should use solver primitives instead of concrete adapters directly"
+
+[[boundaries]]
+from = "crates/arco-ops/src/**"
+to = "crates/arco-scip/src/**"
+reason = "arco-ops should use solver primitives instead of concrete adapters directly"
+
+[[boundaries]]
+from = "crates/arco-blocks/src/**"
+to = "crates/arco-kdl/src/**"
+reason = "Block composition must not depend on authoring-surface internals"
+
+[[boundaries]]
+from = "crates/arco-blocks/src/**"
+to = "crates/arco-validate/src/**"
+reason = "Block composition must route validation through arco-ops"
+
+[[boundaries]]
+from = "crates/arco-blocks/src/**"
+to = "crates/arco-format/src/**"
+reason = "Block composition must route format/export through arco-ops"
+
+[[boundaries]]
+from = "crates/arco-blocks/src/**"
+to = "crates/arco-solver/src/**"
+reason = "Block composition must route solving through arco-ops"