packaging(debian-upstream): set up salsa.debian.org git repo (php-team/php-firebird.git)

[satwareAG-ironMike]

Context

Debian packages are maintained in Git on salsa.debian.org (Debian's GitLab instance). The PHP team has a group at https://salsa.debian.org/php-team/. We need to create the php-firebird.git repo there and push our packaging branch.

This is the canonical source for the Debian package — once accepted, all future updates are pushed there.

Acceptance Criteria

• Salsa account created for satware AG (or existing Debian developer account used)
• Repo created: salsa.debian.org/php-team/php-firebird.git
• debian/ directory pushed to main branch (or debian/main per team convention)
• Upstream source pushed to upstream branch (or tagged)
• debian/gbp.conf configured (git-buildpackage settings)
• CI pipeline on Salsa runs lintian + sbuild on push
• README on Salsa points to upstream GitHub repo
• Access granted to Debian PHP team (merge request permissions)

Dependencies

• Bug: Column alias deduplication fails on padded aliases (Firebird 3.0) #23 (ITP filed) — Debian team must acknowledge before repo setup
• Build Windows DLLs with GitHub Actions using php-windows-builder #24 (packaging polished) — packaging must meet Debian standards
• Debian sponsor/advocate (a Debian Developer must create the Salsa repo)

Suggested Test Plan

1. git clone salsa.debian.org:php-team/php-firebird.git — succeeds
2. gbp buildpackage — builds from Salsa repo
3. Salsa CI pipeline passes
4. First sponsor upload (dput) to Debian unstable succeeds