- envd: reject non-regular files (devices, pipes, sockets) in GetFiles
to prevent infinite reads from /dev/zero, /dev/urandom etc.
- host agent: add context cancellation check in ReadFileStream loop
with proper Connect error codes
- frontend: abort in-flight file reads on file switch, directory
navigation, and component teardown via AbortController
- frontend: guard against abort errors surfacing in UI, use try/finally
for fileLoading state