feat: desktop computer-use APIs with windows, launch/open, and neko streaming

Adds desktop computer-use endpoints (windows, screenshots, mouse/keyboard,
launch/open), enhances neko-based streaming integration, updates inspector
UI with desktop debug tab, and adds common software test infrastructure.

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

docker/test-common-software/Dockerfile

@@ -0,0 +1,37 @@
+# Extends the base test-agent image with common software pre-installed.
+# Used by the common_software integration test to verify that all documented
+# software in docs/common-software.mdx works correctly inside the sandbox.
+#
+# KEEP IN SYNC with docs/common-software.mdx
+
+ARG BASE_IMAGE=sandbox-agent-test:dev
+FROM ${BASE_IMAGE}
+
+USER root
+
+RUN apt-get update -qq && \
+    apt-get install -y -qq --no-install-recommends \
+      # Browsers
+      chromium \
+      firefox-esr \
+      # Languages
+      python3 python3-pip python3-venv \
+      default-jdk \
+      ruby-full \
+      # Databases
+      sqlite3 \
+      redis-server \
+      # Build tools
+      build-essential cmake pkg-config \
+      # CLI tools
+      git jq tmux \
+      # Media and graphics
+      imagemagick \
+      poppler-utils \
+      # Desktop apps
+      gimp \
+      > /dev/null 2>&1 && \
+    rm -rf /var/lib/apt/lists/*
+
+ENTRYPOINT ["/usr/local/bin/sandbox-agent"]
+CMD ["server", "--host", "0.0.0.0", "--port", "3000", "--no-token"]