supports small llama and gemma models

Refactor inference

dedicated crates for llama and gemma inferencing, not integrated

crates/inference-engine/src/inference.rs

@@ -0,0 +1,33 @@
+use anyhow::Result;
+use candle_core::Tensor;
+
+/// ModelInference trait defines the common interface for model inference operations
+///
+/// This trait serves as an abstraction for different model implementations (Gemma and Llama)
+/// to provide a unified interface for the inference engine.
+pub trait ModelInference {
+    /// Perform model inference for the given input tensor starting at the specified position
+    ///
+    /// # Arguments
+    ///
+    /// * `input_ids` - The input tensor containing token IDs
+    /// * `pos` - The position to start generation from
+    ///
+    /// # Returns
+    ///
+    /// A tensor containing the logits for the next token prediction
+    fn forward(&mut self, input_ids: &Tensor, pos: usize) -> Result<Tensor>;
+
+    /// Reset the model's internal state, if applicable
+    ///
+    /// This method can be used to clear any cached state between inference requests
+    fn reset_state(&mut self) -> Result<()>;
+
+    /// Get the model type name
+    ///
+    /// Returns a string identifier for the model type (e.g., "Gemma", "Llama")
+    fn model_type(&self) -> &'static str;
+}
+
+/// Factory function type for creating model inference implementations
+pub type ModelInferenceFactory = fn() -> Result<Box<dyn ModelInference>>;