WIP 5 add image embedding provider (local only for now)

src/rpc.rs

@@ -996,6 +996,7 @@ impl RpcServer for RpcServerImpl {
         }
         let prov = match provider.to_lowercase().as_str() {
             "test-hash" | "testhash" => EmbeddingProvider::TestHash,
+            "testimagehash" | "image-test-hash" | "imagetesthash" => EmbeddingProvider::ImageTestHash,
             "fastembed" | "lancefastembed" => EmbeddingProvider::LanceFastEmbed,
             "openai" | "lanceopenai" => EmbeddingProvider::LanceOpenAI,
             other => EmbeddingProvider::LanceOther(other.to_string()),
@@ -1030,6 +1031,7 @@ impl RpcServer for RpcServerImpl {
         Ok(serde_json::json!({
             "provider": match cfg.provider {
                 EmbeddingProvider::TestHash => "test-hash",
+                EmbeddingProvider::ImageTestHash => "testimagehash",
                 EmbeddingProvider::LanceFastEmbed => "lancefastembed",
                 EmbeddingProvider::LanceOpenAI => "lanceopenai",
                 EmbeddingProvider::LanceOther(ref s) => s,