Audit Log tab: support editing user operation annotations (C7 EE Cockpit parity)

[javahippie]

Summary

Follow-up to #93 (Audit Log tab): C7 EE Cockpit additionally allows setting and clearing an annotation on user operation log entries. The read-only Audit Log tab proposed in #93 displays the annotation column but offers no way to edit it.

Expected (C7 EE Cockpit parity)

Each audit log entry offers an "edit annotation" action; saving calls

PUT /history/user-operation/{operationId}/set-annotation   { "annotation": "..." }
PUT /history/user-operation/{operationId}/clear-annotation

(both community REST endpoints), then reloads the log.

Suggested implementation

• Two new functions in src/api/resources/history.js (set_user_operation_annotation, clear_user_operation_annotation).
• Inline edit affordance in the annotation column of the Audit Log tab (Process instance history view: add "Audit Log" tab (user operation log, C7 Cockpit parity) #93), e.g. click-to-edit with save/clear, guarded by a confirmation for clear.
• Note: an operation id groups multiple log entries (one per changed property); the annotation applies to the whole operation — the UI should edit per operationId, not per table row.