Dispatch Content Scout artifacts offline

[ferueda]

Summary

• prepare bounded Content Scout input from exact retained claims, facts, and evidence
• enforce privacy, disclosure, provenance, and all-or-nothing output admission
• dispatch retained jobs through the generic executor boundary
• correlate execution receipts and finalize cancellation and failure paths safely
• produce terminal runs and review-required artifact-backed content ideas

Review path

1. Start with internal/application/content_scout_dispatcher.go for the orchestration flow.
2. Read internal/application/content_scout.go for bounded preparation and lineage checks.
3. Read internal/application/content_scout_admission.go and content_disclosure.go for result admission.
4. Read internal/integration/content_scout_dispatcher_test.go for the complete offline path.
5. Use the focused tests for mismatched receipts, cancellation, privacy, omissions, and fact lineage.

Boundaries

This PR has no schema migration, legacy cleanup, Eve adapter, TypeScript agent, or live model call. It uses a fake executor in routine tests.

Verification

• make check
• final implementation and quality reviews previously passed with zero findings

Stack

Based on #23. Merge and reconcile the parent PRs first.

[ferueda]

Superseded by #20. Content preparation, disclosure policy, agent dispatch, result admission, and content artifacts belong to the independent Content Scout consumer. The branch remains available as reference; this implementation will not enter Noema.