Add cancel + progress UI, EngineToggle, and Docker deployment

.dockerignore

@@ -1,3 +1,5 @@
+# Only what the Dockerfile COPYs matters: package.json/bun.lock/bunfig.toml,
+# src/, scripts/, server-py/. Everything else is noise for the build context.
 .git
 node_modules
 dist
@@ -7,3 +9,21 @@ tests
 .gitlab-ci.yml
 Dockerfile
 .dockerignore
+docker-compose.yml
+
+# Python bytecode caches (server-py/ is COPY'd into the image)
+__pycache__/
+*.pyc
+
+# Editor / agent state
+.idea
+.claude
+
+# Local env files — configuration is runtime `-e` flags (D-015), never baked in
+.env
+.env.*
+
+# Misc local output
+coverage
+logs
+*.log