[harmony] Bug 2051802: Abort UTF8 conversion without an explicit override

[justdave]

Details

When Docker hits the non-interactive UTF-8 conversion bailout, console output now prints a clear hint showing how to proceed explicitly:

BZ_ALLOW_UNSAFE_UTF8_CONVERSION=1 docker compose up

What changed

1. Removed the NO_PAUSE gating on the UTF8 conversion to force it to bail even if NO_PAUSE is active
2. New Docker env var is wired into the generated answers file
3. Checksetup DB code now honors ALLOW_UNSAFE_UTF8_CONVERSION=1 in non-interactive mode (instead of always dying at that point)
4. User-facing setup text updated to document the answers-file override
5. Docker quick-start README note added: bugzilla/README

Net effect

1. If you do nothing, behavior stays safe (default is 0, so it still blocks).
2. If you explicitly opt in, conversion runs non-interactively.
3. If conversion blocks and exits, Docker no longer pretends setup succeeded.

Additional info

• bug#2051802

Test Plan

1. Ran docker compose up
2. After it came up, used the Files tab in Docker Desktop to drop a database dump from 5.06 into the root directory on the MySQL container
3. Used the Exec tab in Docker Desktop to open a shell and restore that dump into the database.
4. Ran docker compose down
5. Ran docker compose up and verified that the conversion bailed with the new messaging.
6. Ran ALLOW_UNSAFE_UTF8_CONVERSION=1 docker compose up and verified that the conversion proceeded.