Add dev branch deployment pipeline and Proxmox upgrade script

[anishapant21]

Summary

Adds automated .deb package publishing for the dev branch and a one-command upgrade script for Proxmox LXC containers.

Changes
CI/CD — [build-and-release.yml]

• Added dev branch to push and PR triggers
• Added dev-release job: creates/updates a rolling dev-latest pre-release on GitHub Releases on every push to dev
• Dev packages are prefixed with dev- to distinguish from stable releases
• Stable release jobs (create-release, publish-npm, update-homebrew) remain gated on v* tags only

Systemd service — [ldap-gateway.service]

• Fixed ExecStart path: (nfpm [type: tree] copies server contents directly to /opt/ldap-gateway/)
• Fixed ReadWritePaths for cert directory to match
• Added ReadOnlyPaths=/mnt/pve /mnt/priv for Proxmox backend config file access through ProtectSystem=strict sandbox

Upgrade script — [proxmox-upgrade.sh]

• One-command upgrade for Proxmox containers
• ldap-gateway-upgrade --dev — pulls latest dev build
• ldap-gateway-upgrade — pulls latest stable release
• ldap-gateway-upgrade v1.2.0 — pulls specific version
• SHA256 checksum verification, temp dir cleanup, service status reporting

How to use
Testing

• Push to dev triggers build-and-release workflow
• dev-release job creates dev-latest pre-release with .deb assets
• ldap-gateway-upgrade --dev downloads and installs successfully
• Service starts and binds on port 636
• /etc/default/ldap-gateway config preserved across upgrades
• Stable release jobs (create-release, publish-npm) do NOT trigger on dev pushes

[Copilot]

Pull request overview

Adds a dev-branch delivery path (rolling dev-latest GitHub pre-release with packages) and a Proxmox LXC upgrade helper, plus systemd hardening/path fixes to match nfpm’s install layout.

Changes:

• Extend CI triggers to include dev and add a dev-release job that publishes a rolling dev-latest pre-release with dev--prefixed package assets and checksums.
• Update the packaged systemd unit to start the correct entrypoint and adjust sandbox path allowances (cert dir and Proxmox mountpoints).
• Add a Proxmox/Debian upgrade script that downloads a release asset, verifies SHA256 (when available), installs it, and reports service status.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.

File	Description
scripts/proxmox-upgrade.sh	New one-command upgrade script for installing stable/dev .deb releases with optional checksum verification.
nfpm/systemd/ldap-gateway.service	Fix ExecStart/cert path to align with nfpm’s /opt/ldap-gateway/ tree install; allow read-only access to Proxmox mount paths.
.github/workflows/build-and-release.yml	Add dev triggers and a rolling dev-latest pre-release publisher job.