* fix(backup): detect pg server major for version-aware pg_dump hints
pg_dump aborts when its major version is older than the server's, so
backup preflight now runs SHOW server_version_num against the live PG
server and uses the detected major to drive:
- the missing-pg_dump hint (names the exact postgresqlNN-client)
- a new compat check that flags an installed-but-too-old pg_dump as
not-ready, instead of letting backup fail partway through the dump
Adds ParsePgDumpMajor helper for Debian/Homebrew/EDB output shapes,
covered by table-driven unit tests. Normalizes nil ctx once at
RunPreflight boundary so downstream exec.CommandContext calls are safe.
Stubs detectPGServerMajor + checkPgDumpServerCompat for the sqliteonly
build.
UI: removes the duplicate static hint from the preflight alert box so
the dynamic, actionable warning is the single source of truth. Drops
the obsolete pgDumpHint i18n key from en/vi/zh locale files.
Refs #829
* fix(docker): bump runtime base alpine 3.22 → 3.23
Alpine 3.23 main ships postgresql16-client, postgresql17-client, and
postgresql18-client simultaneously. Alpine 3.22 only shipped up to
postgresql17-client, so the backup preflight's dynamic hint to install
postgresql18-client previously failed with "no such package" on PG 18
deployments.
No client package is pre-bundled: the on-demand install via the
Packages page now resolves for any supported PG major.
Refs #829
