Freeze lab-tested PostgreSQL plugin engine

Extract PostgreSQL, Podman runtime and systemd lifecycle adapters while preserving existing lifecycle and scoring behavior. Update RPM layout and add guarded operator-run lab harnesses.

Record successful manual stop/start, promotion, demotion and rewind-only rejoin with pinned installed hashes. The unfenced lab does not validate automatic failover, Pacemaker-managed transitions or divergent-data rewind.

Validation: 103 offline tests, original-function differential checks, checksum manifest and whitespace checks passed.

packaging/README.md

@@ -5,7 +5,7 @@ Fedora 43, matching the saved lab package context. The workstation currently
 reports Fedora 44; this first workflow does not claim a Fedora 44 build test.
 It runs on main pushes, pull requests and manual dispatch.
 
-The build installs only the OCF executable and nine shell modules, one Python state helper, plus documentation.
+The build installs only the OCF executable and 13 shell modules, one Python state helper, plus documentation.
 It includes no Quadlet, secrets, databases or cluster configuration. There are
 no RPM lifecycle scriptlets. Installation does not start, stop or restart a
 service or change maintenance mode. Host PostgreSQL packages are not required.
@@ -85,3 +85,7 @@ The disconnected candidate adds a runtime Python 3 dependency and advertises
 Current operating policy and operator-reported production validation are packaged
 from `docs/`. The source freeze is distinct from verified deployed-byte identity;
 see [testing](../docs/testing.md) for production snapshot status.
+
+The plugin extraction adds three selectors, defaulting to PostgreSQL/Podman/systemd.
+The package includes all API-1 plugin files and `plugin-engine.md`; Docker and
+direct-runtime lifecycle management are not implemented.