eval(deltawire): integrate terminal v6 runtime boundary

[bigboateng]

Summary

Integrates the reusable DeltaWire v6 runtime boundary into main without raw experiment evidence. The terminal v6 experiment remains immutable on PR #115 and is verified through Git objects at commits 0dad5c0 and 273e977.

Changes

• Adds the preinstalled Gemini agent, pinned runtime identity, conformance task, receipt validators, and trial normalization.
• Adds a terminal v6 evidence lock covering 68 pre-pair and 107 terminal files.
• Replaces repository-state-dependent release testing with isolated temporary fixtures.
• Adds a no-live-call runtime workflow and compact public terminal classification.

Evidence boundary

No raw Harbor jobs, logs, trajectories, expanded output, approvals, credentials, or VM paths are projected into this PR.

Validation

• Full DeltaWire Go/race/20x/vet/runtime/determinism/contract/cleanliness suite
• V1–v6 evidence-lock verification and mutation controls
• Environment, artifact, setup, shell-observation, and trial-status tests
• Harbor 0.20.0 custom-agent inheritance tests
• Temporary-fixture content-addressed release tests

READY_FOR_72=false. This PR performs no model calls and authorizes no experiment.