feat(embeddings): add embedding model support and related changes

* Introduced EmbeddingModel method in Client and Provider interfaces
* Updated InsertThought and SearchThoughts methods to handle embedding models
* Created embeddings table and updated match_thoughts function for model filtering
* Removed embedding column from thoughts table
* Adjusted permissions for new embeddings table

internal/tools/context.go

@@ -76,7 +76,7 @@ func (t *ContextTool) Handle(ctx context.Context, req *mcp.CallToolRequest, in P
 		if err != nil {
 			return nil, ProjectContextOutput{}, err
 		}
-		semantic, err := t.store.SearchSimilarThoughts(ctx, embedding, t.search.DefaultThreshold, limit, &project.ID, nil)
+		semantic, err := t.store.SearchSimilarThoughts(ctx, embedding, t.provider.EmbeddingModel(), t.search.DefaultThreshold, limit, &project.ID, nil)
 		if err != nil {
 			return nil, ProjectContextOutput{}, err
 		}