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.

signal_classes.ttl

@@ -0,0 +1,31 @@
+@prefix dlo: <https://www.tnopsi.com/dslo/> .
+
+dlo:MeaningBearingSignal
+    a dlo:SignalClass ;
+    dlo:hasLabel "Meaning‑Bearing Signal" ;
+    dlo:hasDescription "Signals whose meaning remains anchored to their substrate and context." .
+
+dlo:SyntheticSignal
+    a dlo:SignalClass ;
+    dlo:hasLabel "Synthetic Signal" ;
+    dlo:hasDescription "Signals generated or transformed by artificial substrates with statistical posture." .
+
+dlo:DriftedSignal
+    a dlo:SignalClass ;
+    dlo:hasLabel "Drifted Signal" ;
+    dlo:hasDescription "Signals whose coherence or meaning has degraded due to drift pressure." .
+
+dlo:StabilizedSignal
+    a dlo:SignalClass ;
+    dlo:hasLabel "Stabilized Signal" ;
+    dlo:hasDescription "Signals restored or reinforced through corrective or invariant‑preserving mechanisms." .
+
+dlo:CorrectiveSignal
+    a dlo:SignalClass ;
+    dlo:hasLabel "Corrective Signal" ;
+    dlo:hasDescription "Signals designed to restore coherence, re‑anchor meaning, or counteract drift." .
+
+dlo:SubstrateAnchoredSignal
+    a dlo:SignalClass ;
+    dlo:hasLabel "Substrate‑Anchored Signal" ;
+    dlo:hasDescription "Signals tightly coupled to the substrate they represent, resisting decoupling drift." .