Add explicit adoption planning front door

[iperev]

Summary

• replace the ambiguous init surface with repository-inventory and adopt plan
• bind route grammar, agent-route input identity, generated adapters, and installed npm/wheel contracts to explicit owners
• add bounded repository discovery and deterministic adoption plans for supported repository classes
• strengthen package carrier, process-lifecycle, coverage, and version-edge proof

Validation

• npm exec --yes --package npm@12.0.2 -- npm run check
• go test ./internal/app ./internal/kernel/commandroute ./internal/tools/packageverify ./internal/tools/pythonpackage -count=1
• npm exec --yes --package npm@12.0.2 -- npm run python:verify
• npm exec --yes --package npm@12.0.2 -- npm run platform:smoke
• git diff --check origin/main...HEAD

Review

Two independent supervised multi-agent rounds covered architecture/authority, runtime regressions, package carriers, and adversarial closeout. All confirmed findings were corrected before this PR.

Non-claims

This PR does not prove registry publication, provider attestation, consumer rollout, or production readiness. TSX remains outside the supported TypeScript scanner contract. Exact macOS-floor execution remains deferred until a maintained macOS 13 runner exists.