docs: refine source and Home Runtime intake contract

[hindermath]

Summary

• refine documentation intakes D4-D7 with the canonical Level 0 source, manifest-managed Home-Baseline Runtime, sourceOnly, and machineLocal boundaries
• document runtime contents, benefits, one-way sync, edit authority, host/container limits, and portable Level 1/2 adoption rules
• supersede the stale D4-D7 and Series review evidence without starting downstream work
• reconcile the receipt and Series hashes missed by PR fix: restore SecureCaseTracker workspace paths #176 for positions 24 and 31 without changing either rollout intake
• record one remaining Medium finding in each refreshed rollout review: the Level 1 name still uses secure-casetracker-baseline instead of the canonical SecureCaseTrackerProjects path

Documentation impact

UpdateRequired — the D4-D7 intakes, active order, receipts, review lineage, Series evidence, and statistics ledger are updated. Runtime behavior and the Home sync manifest are unchanged.

Validation

• Bash and PowerShell receipt validators: six current receipts
• Bash and PowerShell review validators: two current NeedsRemediation reviews
• Bash and PowerShell Series validators: 37 targets, 3 roots, 44 dependencies, D4 sole declared Eligible target
• intake authoring lifecycle, authoring validator, intake review validator, and sequencing validator suites
• byte-identical archive checks for all six superseded intake targets
• git diff --check
• gitleaks / pre-push secret scan
• Statistics Profile 2: CURRENT

No D4-D7 feature, learner Spec Kit run, downstream propagation, or writeful Home sync was started.