fix: add explicit embedding initialization with error logging

When embeddings fail to initialize in the MCP server context (e.g., due
to working directory issues), the error was silently swallowed and
smart_ingest would fall back to regular ingest without explanation.

Changes:
- Add init_embeddings() method to Storage for explicit initialization
- Initialize embeddings at MCP server startup with error logging
- Add check_ready() method to EmbeddingService for error access
- Log warning when is_ready() returns false

Now users will see clear error messages like:
"Failed to initialize embedding service: ..."
"Hint: Check FASTEMBED_CACHE_PATH or ensure ~/.fastembed_cache exists"

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

crates/vestige-mcp/src/main.rs

@@ -133,8 +133,21 @@ async fn main() {
 
     // Initialize storage with optional custom data directory
     let storage = match Storage::new(data_dir) {
-        Ok(s) => {
+        Ok(mut s) => {
             info!("Storage initialized successfully");
+
+            // Try to initialize embeddings early and log any issues
+            #[cfg(feature = "embeddings")]
+            {
+                if let Err(e) = s.init_embeddings() {
+                    error!("Failed to initialize embedding service: {}", e);
+                    error!("Smart ingest will fall back to regular ingest without deduplication");
+                    error!("Hint: Check FASTEMBED_CACHE_PATH or ensure ~/.fastembed_cache exists");
+                } else {
+                    info!("Embedding service initialized successfully");
+                }
+            }
+
             Arc::new(Mutex::new(s))
         }
         Err(e) => {