flake/devshell: avoid read-only mode on copied appview static files
The devshell copied assets from the Nix store with preserved mode
bits, which left files in appview/pages/static read-only and caused
repeated cp permission errors on subsequent nix develop runs.
Stop preserving mode so generated static files remain writable across
shell entries.
AI-assisted: OpenCode (openai/gpt-5.3-codex)
Signed-off-by: Alessio Caiazza <code.git@caiazza.info>
authored by
tangled.org
2286c057
da1a4747