Postmaster v9.4.3 task visibility and detail view

[the-code-learner]

Summary

• add read-only get_job(job_id) as the complete task detail view
• hide persisted completed tasks from list_jobs() by default
• add include_completed while preserving explicit status="completed" semantics and existing owner/project/status filters
• apply limit after completed-task visibility filtering
• return one structured {ok, count, jobs} MCP result while preserving existing job record fields
• report task_detail_view and completed_tasks_hidden_by_default capabilities
• keep completed as the persisted database status; no deletion, archive or migration

Compatibility

Unchanged: create_job, complete_job, recurring advancement, list_due_jobs, approval/security behavior, registry persistence, scheduler autonomous-execution policy, and scheduler_status completed counts.

postmaster-mcp.yml is unchanged. No new environment variables, ports, volumes, Cloudflare changes, or deployment-specific migrations.

Tests

Adds tests/test_v9_4_3_task_visibility.py covering default/explicit completed visibility, filters, post-filter limit, complete detail/not-found behavior, persistence/counting, due/create/complete/recurring regressions, MCP tool schema/serialization, and build capabilities.

The required v9 runtime tests / test workflow also runs the full existing mail/account/knowledge suite, provider-neutral public-tree scan, and single-YAML bootstrap validations.