Widens the salvaged .env injection fix (#50315) to the sibling site it
missed: hermes_cli/memory_setup.py::_write_env_vars is the near-identical
core writer the openviking plugin's copy was forked from, is fed directly
by interactive _prompt() (pasted API keys), and is reused by other memory
plugins (e.g. supermemory imports it). A pasted secret with an embedded
CR/LF injected an arbitrary extra KEY=VALUE line on the next read.
Same _env_line_safe() treatment as the plugin writer (strip every
str.splitlines() separator + NUL), matching config.save_env_value's
existing newline strip. Mutation-checked: reverting the sanitizer makes
the new regression tests fail.
Support linking, copying, and creating ovcli.conf during OpenViking memory setup.
Make setup cancellation write nothing and cover OpenViking/Hindsight picker cancellation paths.