Add MoQ devcontainer verification

Switch devcontainers to Debian Trixie for the required glibc version and add automated MoQ package tests, Agent linking, and version checks through a script and VS Code task.

machinery/verify-moq-devcontainer.sh

@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+required_glibc="2.38"
+current_glibc="$(getconf GNU_LIBC_VERSION | awk '{print $2}')"
+
+if ! dpkg --compare-versions "$current_glibc" ge "$required_glibc"; then
+    echo "MoQ requires glibc ${required_glibc}+; this container has ${current_glibc}." >&2
+    echo "Rebuild the devcontainer with the Trixie base, then run this check again." >&2
+    exit 1
+fi
+
+echo "==> Testing MoQ packages (glibc ${current_glibc})"
+GOWORK=off go test -tags moq ./src/cloud/livemoq ./src/cloud
+
+binary="${TMPDIR:-/tmp}/agent-moq"
+trap 'rm -f "$binary"' EXIT
+
+echo "==> Linking the MoQ Agent"
+GOWORK=off go build -tags moq -o "$binary" ./main.go
+
+echo "==> Running the linked binary"
+"$binary" -action version