feat: migrate embeddings to Candle WASM + remove semantic type inference

Major architectural changes:

1. EMBEDDINGS ENGINE (ONNX → Candle WASM):
   - Replace ONNX Runtime with Rust Candle compiled to WASM
   - Embedded model in WASM binary (no external downloads)
   - Quantized Q8 precision with <50MB memory footprint
   - Zero-download, offline-first operation
   - Same embedding quality (all-MiniLM-L6-v2)

2. REMOVE SEMANTIC TYPE INFERENCE:
   - Delete embeddedKeywordEmbeddings.ts (14MB of pre-computed embeddings)
   - Remove typeAwareQueryPlanner.ts and semanticTypeInference.ts
   - Remove VerbExactMatchSignal (uses keyword embeddings)
   - Update SmartRelationshipExtractor to 3 signals (55%/30%/15% weights)

API CHANGES (requires v7.0.0):
- Removed: inferTypes(), inferNouns(), inferVerbs(), inferIntent()
- Removed: getSemanticTypeInference(), SemanticTypeInference class
- Removed: TypeInference, SemanticTypeInferenceOptions types

Users can still use natural language queries in find() - they just
need to specify type explicitly for type-optimized searches.

PACKAGE SIZE IMPACT:
- Compressed: 90.1 MB → 86.2 MB (-4.3%)
- Uncompressed: 114.4 MB → 100.3 MB (-12%)
- ~448K lines of code removed

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/utils/embedding.ts

@@ -1,8 +1,8 @@
 /**
  * Embedding functions for converting data to vectors
  *
- * Uses direct ONNX WASM for universal compatibility.
- * No transformers.js dependency - clean, production-grade implementation.
+ * Uses Candle WASM for universal compatibility.
+ * No transformers.js or ONNX Runtime dependency - clean, production-grade implementation.
  */
 
 import { EmbeddingFunction, EmbeddingModel, Vector } from '../coreTypes.js'
@@ -27,10 +27,10 @@ export interface TransformerEmbeddingOptions {
 }
 
 /**
- * TransformerEmbedding - Sentence embeddings using WASM ONNX
+ * TransformerEmbedding - Sentence embeddings using Candle WASM
  *
  * This class delegates all work to EmbeddingManager which uses
- * the direct ONNX WASM engine. Kept for backward compatibility.
+ * the Candle WASM engine. Kept for backward compatibility.
  */
 export class TransformerEmbedding implements EmbeddingModel {
   private initialized = false
@@ -40,7 +40,7 @@ export class TransformerEmbedding implements EmbeddingModel {
     this.verbose = options.verbose !== undefined ? options.verbose : true
 
     if (this.verbose) {
-      console.log('[TransformerEmbedding] Using WASM ONNX backend (delegating to EmbeddingManager)')
+      console.log('[TransformerEmbedding] Using Candle WASM backend (delegating to EmbeddingManager)')
     }
   }