Separate workspace report computation from compatibility facade

[codeforester]

Context

cli/python/base_projects/workspace_reports.py still combines workspace status/check computation, repo metadata attachment, last-check lookup, and compatibility re-exports for JSON/text rendering. Rendering has already been split, but computation and facade responsibilities are still coupled.

Scope

• Extract workspace status/check computation into focused modules.
• Leave workspace_reports.py as a narrow facade if needed for compatibility.
• Preserve JSON/text report output behavior.

Validation

• Focused workspace status/check tests.
• Existing workspace report tests.
• git diff --check.