feat: GPU/TensorCore integration — TensorFlow backend, GPU-accelerated reasoning, training, and memory

- New fusionagi/gpu/ module with TensorBackend protocol abstraction
  - TensorFlowBackend: GPU-accelerated ops with TensorCore mixed-precision
  - NumPyBackend: CPU fallback (always available, no extra deps)
  - Auto-selects best available backend at runtime

- GPU-accelerated operations:
  - Cosine similarity matrix (batched, XLA-compiled)
  - Multi-head attention for consensus scoring
  - Batch hypothesis scoring on GPU
  - Semantic similarity search (pairwise, nearest-neighbor, deduplication)

- New TensorFlowAdapter (fusionagi/adapters/):
  - LLMAdapter for local TF/Keras model inference
  - TensorCore mixed-precision support
  - GPU-accelerated embedding synthesis fallback

- Reasoning pipeline integration:
  - gpu_scoring.py: drop-in GPU replacement for multi_path scoring
  - Super Big Brain: use_gpu config flag, GPU scoring when available

- Memory integration:
  - gpu_search.py: GPU-accelerated semantic search for SemanticGraphMemory

- Self-improvement integration:
  - gpu_training.py: gradient-based heuristic weight optimization
  - Reflective memory training loop with loss tracking

- Dependencies: gpu extra (tensorflow>=2.16, numpy>=1.26)
- 64 new tests (276 total), all passing
- Architecture spec: docs/gpu_tensorcore_integration.md

Co-Authored-By: Nakamoto, S <defi@defi-oracle.io>

fusionagi/gpu/__init__.py

@@ -0,0 +1,56 @@
+"""GPU-accelerated tensor operations for FusionAGI.
+
+Auto-selects the best available backend:
+- TensorFlow with TensorCore/mixed-precision (when installed)
+- NumPy CPU fallback (always available)
+
+Install GPU support: pip install fusionagi[gpu]
+"""
+
+from fusionagi.gpu.backend import (
+    DeviceType,
+    NumPyBackend,
+    TensorBackend,
+    get_backend,
+    reset_backend,
+)
+from fusionagi.gpu.tensor_attention import (
+    attention_consensus,
+    cross_claim_attention,
+)
+from fusionagi.gpu.tensor_scoring import (
+    gpu_score_claims_against_reference,
+    gpu_score_hypotheses,
+)
+from fusionagi.gpu.tensor_similarity import (
+    deduplicate_claims,
+    nearest_neighbors,
+    pairwise_text_similarity,
+)
+from fusionagi.gpu.training import (
+    TrainingConfig,
+    TrainingResult,
+    optimize_heuristic_weights,
+    prepare_training_pairs,
+    run_gpu_training,
+)
+
+__all__ = [
+    "DeviceType",
+    "NumPyBackend",
+    "TensorBackend",
+    "get_backend",
+    "reset_backend",
+    "deduplicate_claims",
+    "nearest_neighbors",
+    "pairwise_text_similarity",
+    "attention_consensus",
+    "cross_claim_attention",
+    "gpu_score_claims_against_reference",
+    "gpu_score_hypotheses",
+    "TrainingConfig",
+    "TrainingResult",
+    "optimize_heuristic_weights",
+    "prepare_training_pairs",
+    "run_gpu_training",
+]