Support reading/writing Publisher `.posit/` deployment records (in addition to `rsconnect-python/*.json`)

Summary

rsconnect-python and the Posit Publisher (VS Code extension) currently track deployments in two mutually exclusive, incompatible formats. A directory deployed with one tool is invisible to the other, so the two toolchains can't collaborate on the same content. I'd like rsconnect-python to be able to read (and eventually write) the Publisher's .posit/ records so all of our deployment tooling speaks the same language.

Current behavior

Deploying the same app two ways produces two independent record sets that neither tool reconciles:

Publisher (.posit/publish/) — TOML, with a public versioned schema:

• .posit/publish/<config>.toml — configuration (posit-publishing-schema-v3.json)
• .posit/publish/deployments/<deployment>.toml — deployment record (posit-publishing-record-schema-v3.json), including server_url, content id/GUID, bundle_id, dashboard_url, direct_url, deployed files, requirements, etc.

rsconnect-python (rsconnect-python/<name>.json) — JSON keyed by server URL, with app_id, app_guid, app_url, app_mode, app_store_version.

Because rsconnect-python only knows about its own rsconnect-python/*.json store, a re-deploy via the CLI won't find or update the Publisher's record (and creates a separate piece of content rather than updating the existing one).

Requested behavior

• On deploy/redeploy, have rsconnect-python detect an existing .posit/ directory and use those records to resolve the target server + existing content (GUID/id) for update-in-place.
• Treat this as an addition, not a replacement of the existing rsconnect-python/*.json behavior initially, so we can begin transitioning without breaking existing workflows.
• The Publisher schema is public and versioned, which makes it a good shared source of truth:
  • Config: https://cdn.posit.co/publisher/schemas/posit-publishing-schema-v3.json
  • Record: https://cdn.posit.co/publisher/schemas/posit-publishing-record-schema-v3.json

Why

The Publisher approach is considered the better/preferred way of recording deployments, and aligning rsconnect-python on it means the CLI, the VS Code extension, and other tooling share one deployment source of truth instead of drifting into incompatible records for the same content.

Related issues / prior art