GO-7383 Add resumable JSON onboarding and Heart v0.51.6

[requilence]

Onboarding callers need a machine-readable way to provision an Anytype client and recover interrupted operations without parsing terminal output or creating duplicate accounts, invitations, or API keys. This adds a versioned, non-interactive JSON interface to the native CLI for Hermes and other automation clients.

For example, after a space join returns pending_approval, the caller can resume the same operation ID to inspect membership without resubmitting the invitation. API-key creation similarly recovers an exact credential receipt rather than guessing from an application name.

Changes

• Add schema-v1 JSON results, typed exit states, capabilities, and native inspect commands.
• Support explicit service installation/start, named account creation, private-stdin login, native space join/list/status, and scoped API-key creation/list/revocation.
• Persist operation IDs and intent, coordinate native mutations with an instance lock, and validate account, network, executable, and data-directory bindings before recovery.
• Share credential storage between automation, human CLI commands, and service auto-login. Require explicit secret output; support system keyring storage and an explicit private-file backend for headless instances.
• Publish nonce-verified runtime observations from the existing embedded service. Report uncertain account/listener transitions conservatively; distinguish service liveness from authenticated HTTP API/MCP readiness.
• Upgrade embedded Heart to v0.51.6, including the required any-sync, any-store, and zeroconf dependency updates. Expose the embedded HTTP MCP endpoint and its shared API-key grant through inspection.
• Document the command contract, recovery behavior, and limitations in docs/AUTOMATION.md.

Validation

• make test, make build, and go vet ./... passed on macOS arm64.
• golangci-lint run --new-from-rev=origin/main ./... and go test ./core/automation passed with the repository's Go 1.26.5 toolchain.
• The built binary returns schema-v1 capabilities; build metadata confirms embedded Heart v0.51.6.
• Regression tests cover interrupted operations, account/listener lifecycle ordering, private credential storage, membership states, and exact API-key grant recovery.

Current limits

• Automation manages one default native instance. Machine service provisioning supports macOS launchd and Linux systemd; Windows service automation and account rename are unsupported.
• Previously running CLI services require an explicit upgrade/restart for runtime observation. Inspection does not restart or replace them automatically.
• Tests use isolated fixtures. Live service/account provisioning, remote membership approval, sync, and HTTP MCP acceptance still require a real-client acceptance run.