feat: wire config, component loading, and axum serve in main

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

crates/server/src/main.rs

@@ -1 +1,67 @@
-fn main() {}
+use std::sync::Arc;
+
+use anyhow::Context;
+use tracing::info;
+use tracing_subscriber::EnvFilter;
+
+use whoareyou_server::config::AppConfig;
+use whoareyou_server::fetch::ReqwestFetcher;
+use whoareyou_server::service::{LookupService, ProviderHandle};
+use whoareyou_server::{http, wasm};
+
+#[tokio::main]
+async fn main() -> anyhow::Result<()> {
+    tracing_subscriber::fmt()
+        .with_env_filter(
+            EnvFilter::try_from_default_env().unwrap_or_else(|_| EnvFilter::new("info")),
+        )
+        .init();
+
+    let config = AppConfig::from_env()?;
+
+    let engine = wasm::engine()?;
+    let linker = wasm::linker(&engine)?;
+
+    wasm::spawn_epoch_thread(&engine);
+
+    let mut providers: Vec<Arc<dyn ProviderHandle>> = Vec::new();
+
+    let dir = std::fs::read_dir(&config.components_dir)
+        .with_context(|| format!("reading components dir {:?}", config.components_dir))?;
+
+    for entry in dir {
+        let path = entry?.path();
+
+        if path.extension().is_some_and(|ext| ext == "wasm") {
+            let provider = wasm::WasmProvider::load(&engine, &linker, &path)
+                .with_context(|| format!("loading component {path:?}"))?;
+
+            info!(
+                name = provider.name(),
+                version = provider.version(),
+                ?path,
+                "loaded provider"
+            );
+
+            providers.push(Arc::new(provider));
+        }
+    }
+
+    anyhow::ensure!(
+        !providers.is_empty(),
+        "no .wasm components found in {:?}",
+        config.components_dir
+    );
+
+    let fetcher = Arc::new(ReqwestFetcher::new(config.fetch_timeout)?);
+    let service = Arc::new(LookupService::new(providers, fetcher, config.cache_ttl));
+    let app = http::router(service);
+
+    let listener = tokio::net::TcpListener::bind(config.listen).await?;
+
+    info!("listening on http://{}", config.listen);
+
+    axum::serve(listener, app).await?;
+
+    Ok(())
+}