docs(roadmap): create the holistic execution graph

[szmyty]

What this proposes

• creates the missing ROADMAP.md and an evidence-reconciled 5-step execution snapshot with stable IDs, states, dependencies, outcomes, exit criteria, and current evidence;
• adds strategic context and operating constraints grounded in the existing architecture;
• records visual-roadmap publication as composed at /roadmap/;
• establishes the private, duplicate-aware handoff from ready roadmap steps to future GitHub issue plans.

Current gate: Create the missing roadmap and issue backlog, then certify the 2026-09-01 dataset and evidence rules.

Why this is a draft

This truth update is reviewable now. Merge should wait for the proposed hygiene.roadmap/v1alpha1 contract and Egolint validation path so the metadata is accepted once and adopted consistently.

Safety boundaries

• documentation only;
• no issues are created, closed, or relabeled;
• no workflow, token, Pages setting, or deployment is changed;
• commit volume is not used as progress;
• private issue plans are excluded from public site output.

Roadmap-Step: CIV-Q02