Replace duplicated phase enum in internal/consensus/phase.go with pkg/jobs types

**Epic:** #1081

`internal/consensus/phase.go` currently duplicates phase name constants that are now defined in `pkg/jobs`. Replace the local definitions with imports from `github.com/hashgraph/solo-operator/pkg/jobs`.

## Acceptance Criteria
- [ ] Local phase enum constants removed from `internal/consensus/phase.go`
- [ ] All callers updated to use `jobs.PhaseUpgradePrepare` etc.
- [ ] No behaviour change — pure refactor

Start with internal/consensus/phase.go and inspect the phase constants currently duplicated there. Search for callers of those local constants, update them to use the corresponding pkg/jobs types such as jobs.PhaseUpgradePrepare, and verify that the local enum is gone with no behavior changes.

Written by the indexing model from the issue text.