feat(sagi): flesh out mood animations and add avatar interaction motion

Gives watching/thinking real animations (previously static), adds
character to happy/worried/stuck moods, and adds mount-in/press/error-pulse
motion to the avatar button - all gated by prefers-reduced-motion.

fix(test): pin NODE_ENV=production in client-dist-override.test.js

The suite exercises server/index.js's production-only static-serving
gate but never set NODE_ENV itself, so it silently depended on the
ambient shell's NODE_ENV - failing whenever that wasn't "production".

server/__tests__/client-dist-override.test.js

@@ -21,7 +21,12 @@ fs.mkdirSync(DIST);
 fs.writeFileSync(path.join(DIST, "index.html"), "<!doctype html><title>from-runtime</title>");
 
 // Must be set BEFORE requiring the server: the data dir, discovery file and
-// the static mount are all resolved at startup.
+// the static mount are all resolved at startup. NODE_ENV=production is the
+// gate server/index.js uses to decide whether to serve the client bundle at
+// all - this suite exercises exactly that code path, so it cannot rely on
+// whatever NODE_ENV the ambient shell happens to have.
+const PREV_NODE_ENV = process.env.NODE_ENV;
+process.env.NODE_ENV = "production";
 process.env.CLAUDE_HOME = TMP;
 process.env.DASHBOARD_DB_PATH = path.join(TMP, "test.db");
 process.env.DASHBOARD_LIVENESS_PROBE = "0";
@@ -81,6 +86,7 @@ describe("DASHBOARD_CLIENT_DIST pointing at a missing directory", () => {
 
   after(() => {
     if (srv) srv.close();
+    process.env.NODE_ENV = PREV_NODE_ENV;
   });
 
   it("answers the API and only 404s the UI route", async () => {