§7 M3 wrapped the three plan request bodies in a `{bundle, project}` struct,
silently breaking version-skew compatibility: a pre-§7 `pic plan` POSTs a BARE
bundle at the JSON top level and now fails deserialization (422 "missing field
bundle"), even though the sibling apply request deliberately kept its added
fields additive (`#[serde(default)]`) so an older CLI still works.
`#[serde(flatten)]` the bundle in `PlanRequest`/`TreePlanRequest` so the bundle
fields sit at the top level again: a bare bundle deserializes (`project`
defaults to `None`) and a newer client sends the same fields plus a top-level
`project` key. The CLI now builds that shape via a `plan_body` helper (bundle
object + optional `project`), which an older server also accepts (Bundle has no
`deny_unknown_fields`, so the extra key is ignored) — compatible in both skew
directions. Apply is left unwrapped (it was already `{bundle, ...}` pre-§7).
Pinned by `plan_request_accepts_a_bare_bundle` / `_a_flattened_project` /
`tree_plan_request_accepts_a_bare_bundle` unit tests.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
ffa8b02506