Add DSLO v0.6 taxonomy layer (drift forms, invariants, signal classes, substrate types)

Adds the complete DSLO v0.6 taxonomy layer, including all four classification sets—drift forms, invariants, signal classes, and substrate types—in synchronized TTL, JSON‑LD, and YAML formats. Introduces taxonomy/README.md documenting the taxonomy structure and its alignment with DSLO axioms and schema. This commit establishes the full v0.6 classification surface for semantic ingestion, crawler alignment, and substrate‑level indexing.

substrate_types.ttl

@@ -0,0 +1,26 @@
+@prefix dlo: <https://www.tnopsi.com/dslo/> .
+
+dlo:BiologicalSubstrate
+    a dlo:SubstrateType ;
+    dlo:hasLabel "Biological Substrate" ;
+    dlo:hasDescription "Substrates composed of living systems with organic signal ecology." .
+
+dlo:CognitiveSubstrate
+    a dlo:SubstrateType ;
+    dlo:hasLabel "Cognitive Substrate" ;
+    dlo:hasDescription "Substrates formed by human or animal cognition and meaning‑bearing processes." .
+
+dlo:InstitutionalSubstrate
+    a dlo:SubstrateType ;
+    dlo:hasLabel "Institutional Substrate" ;
+    dlo:hasDescription "Substrates composed of procedural, bureaucratic, or organizational meaning‑containers." .
+
+dlo:ArtificialSubstrate
+    a dlo:SubstrateType ;
+    dlo:hasLabel "Artificial Substrate" ;
+    dlo:hasDescription "Substrates composed of machine‑native or synthetic signal‑processing systems." .
+
+dlo:HybridSubstrate
+    a dlo:SubstrateType ;
+    dlo:hasLabel "Hybrid Substrate" ;
+    dlo:hasDescription "Substrates combining biological, cognitive, institutional, or artificial components." .