docs: consolidate Codex, Grok, and OpenCode runtime status

[vansin]

What

• add one evidence-scoped status page for Codex, Grok, and OpenCode runtime integrations
• separate the shipped Codex Phase-0 preview from the unmerged RFC-030 Policy Gateway production candidate
• correct the Codex 0.144.0 WebSocket Upgrade path to / and mark the RFC-030: wire codex-app-server into anet CLI #441 CLI command as a draft-branch candidate, not a published guarantee
• distinguish the automatic opencode-cli ACP runtime from MCP-only human-driven access
• record the three current OpenCode onboarding gaps: TTY picker/explicit runtime, model propagation, and per-node HOME wiring
• preserve the Grok Round-5 partial verdict and all remaining Phase-1A gates

Why

The existing runtime evidence lives across RFCs, issues, draft PRs, fixtures, and research reports. This page consolidates it without promoting a fixture, source path, or internal freeze into a release claim.

Impact

Docs only. This PR does not unlock RFC-030 §8, Wave 2, merge, deployment, production, package promotion, or latest. It also does not unlock Grok Phase 1A or claim that OpenCode CLI onboarding is complete.

Checks

• git diff --cached --check
• relative evidence links verified against origin/main
• npm preview versions verified with npm view
• public-safety scan: no token prefixes, credential literals, host paths, internal hostnames, or memory slugs
• Codex and OpenCode sections independently source-checked; Grok section remains Draft pending runtime-owner final review