Debian packaging: normalize maintainer scripts, relax libsagui dependency, and harden postinst DB/bootstrap checks

[Al-Muhandis]

Motivation

• Ensure maintainer scripts do not carry CRLF line endings that can break execution on Debian systems.
• Avoid making libsagui a hard dependency so package installs on systems without it still succeed while recommending it.
• Make the postinst script more robust by detecting loader/library availability and handling MySQL root access that requires a password, with clear warnings if bootstrap is skipped.

Description

• Add normalize_maintainer_scripts() to build-deb.sh to strip DOS line endings from DEBIAN/postinst and DEBIAN/postrm, and call it after copying the debian tree into the staging directory.
• Update debian/DEBIAN/control to remove libsagui from Depends and add it as Recommends: libsagui2 | libsagui, and add an Origin field.
• Enhance debian/DEBIAN/postinst by adding libsagui_available() and emitting a warning if the shared library is not found in the dynamic linker cache.
• Change database bootstrap logic in postinst to check whether mysql -u root can run without a password before performing automatic DB creation and schema import, and emit a warning and skip the bootstrap if root access is denied.

Testing

• No automated tests were added or run for these changes.

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Codex Task