[P2][Logs] Standardize log messages and verb choices for searchability

Parent issue: #4691

Intent

Log messages currently use inconsistent verbs, grammar, and message templates. That makes keyword search, grouping, and dashboards less reliable. This task standardizes message wording so similar incidents use stable, searchable text.

Modification points

• Replace low-information templates such as start to, just ignore, and this should not happen with a stable subject + action + result + reason pattern.
• Normalize verb choices for common actions such as start, stop, reset, retry, drop, and ignore.
• Remove grammar issues and repeated wording that do not add meaning.

Entry points

• coordinator/operator/operator_move.go:65
• coordinator/operator/operator_move.go:116
• coordinator/operator/operator_move.go:157
• downstreamadapter/dispatcherorchestrator/dispatcher_orchestrator.go:289
• downstreamadapter/dispatcherorchestrator/dispatcher_orchestrator.go:295
• server/module_election.go:90

Done criteria

• Similar incidents can be found by stable keywords instead of fuzzy free-text matching.
• Message text no longer depends on source code context to be understood.
• Low-information templates and inconsistent verbs are removed from the targeted paths.

Start by inspecting the listed log statements in coordinator/operator/operator_move.go at lines 65, 116, and 157, downstreamadapter/dispatcherorchestrator/dispatcher_orchestrator.go at lines 289 and 295, and server/module_election.go at line 90. Compare their verbs, grammar, templates, and available context, then standardize the targeted messages so similar incidents use stable keywords, express subject, action, result, and reason, and no longer rely on source context.