fix: add lib accessors so examples compile

basic_usage.rs and mlp_router.rs called methods that didn't exist on the
public API (8x E0599). Add thin 1:1 accessor/convenience wrappers:

- Orchestrator::current_project() -> delegates to context manager
- MLP::input_size() / MLP::output_size() -> getters for private fields
- MLP::train_step() -> backward + update, returns the step loss

cargo check --examples is now clean (lib was already fine).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: hyperpolymath

src/mlp.rs

@@ -146,6 +146,24 @@ impl MLP {
         // Phase 2 implementation
     }
 
+    /// Number of input features the network expects.
+    pub fn input_size(&self) -> usize {
+        self.input_size
+    }
+
+    /// Number of output classes the network produces.
+    pub fn output_size(&self) -> usize {
+        self.output_size
+    }
+
+    /// Run one training step: compute loss and gradients via `backward`,
+    /// apply them with `update`, and return the loss for this step.
+    pub fn train_step(&mut self, input: &[f32], target: &[f32], learning_rate: f32) -> f32 {
+        let (loss, gradients) = self.backward(input, target);
+        self.update(&gradients, learning_rate);
+        loss
+    }
+
     /// Argmax: Return the index of the maximum value.
     pub fn argmax(values: &[f32]) -> usize {
         values

src/orchestrator.rs

@@ -88,6 +88,11 @@ impl Orchestrator {
         self.context.switch_project(project);
     }
 
+    /// Borrow the active project name, if one is set.
+    pub fn current_project(&self) -> Option<&str> {
+        self.context.current_project()
+    }
+
     /// Drop the active project's conversation history.
     pub fn clear_history(&mut self) {
         self.context.clear_history();