feat(cli): add versioned IDE JSON output

[vinceblock99]

Summary

• add stable schema-v1 JSON output to atomic status --json
• add local and remote view metadata to atomic view list --json
• keep JSON deterministic, cross-platform, and free of human progress output
• reject malformed remote view inventories instead of returning false empty results, and redact credentials from direct remote URLs
• document the integration contract for editor clients

Supports #171. The companion VS Code extension is submitted separately and consumes this contract.

Test Coverage

• cargo test -p atomic-remote — 216 unit tests and 14 doctests passed
• cargo test -p atomic-cli — 1,840 unit tests plus all integration suites passed
• cargo clippy -p atomic-cli --bin atomic -- -D warnings
• live Atomic repository exercised through the extension client (status, view list, and pristine content) with serialized database access

Pre-Landing Review

Independent API-contract, security, maintainability, testing, and adversarial reviews completed. All findings were fixed; final review reported no findings.

Design Review

No frontend files changed — design review skipped.

Plan Completion

No plan file detected.

Documentation

• atomic-cli/README.md documents the versioned status output, schema compatibility, and view-list integration command.

Test plan

• JSON output is valid and versioned
• status paths are deterministic and correctly escaped
• current/local/remote view metadata is represented consistently
• malformed remote inventory fails instead of becoming a false empty list
• existing human-readable output remains unchanged