Add dashboard attention and workflow aggregate services

[sfmskywalker]

Summary

• add generic Attention aggregation/API with independently registered workflow runtime, secrets, and modularity contributors
• add governed Studio Preferences with scoped CAS persistence on Groundwork SQLite/PostgreSQL
• add exact Workflow Portfolio and Run Health resources, authorization, provider adapters, time-zone buckets, test-run origin, and bounded validation
• make Secrets tenant-authoritative, including v1-to-v2 Groundwork upcasting/backfill and expression isolation

Verification

• Release solution build passed
• Attention Core 10/10; Attention API 4/4; Preferences 16/16; Dashboard 14/14; EF portfolio acceptance 1/1; Architecture 69/69
• all changed suites in the full solution passed
• one unrelated HTTP timeout test fails identically on unchanged baseline commit f152659 (verified in an isolated clean worktree)

Coordinates with elsa-workflows/elsa-foundation-studio#315.

Closes #650
Closes #651
Closes #652