Workspace skeleton: root Cargo.toml becomes a workspace with members
[".", "pmacs-protocol"]; [workspace.dependencies] pins serde,
postcard, thiserror so both crates use byte-identical versions (the
wire format depends on it). pmacs main package keeps its existing
shape (no file moves); it just gains pmacs-protocol as a path
dependency.
Identity types moved: BufferId (from buffer.rs), FrontendId + ByteRange
(from protocol.rs), Position type alias (from rope.rs). All four are
self-contained — no custom-type dependencies — so the first stage of
the move can land atomically without dragging cell/message types along.
src/buffer.rs / src/protocol.rs / src/rope.rs each gain a 'pub use
pmacs_protocol::...' re-export for the moved names, so existing
internal imports (crate::buffer::BufferId, crate::rope::Position, etc.)
continue to resolve unchanged. New consumers (pmacs-gpu, debug tools)
will depend on pmacs-protocol directly.
One visibility change: BufferId::from_raw was pub(crate); promoted to
pub with a doc note that it's not stable API for external consumers.
The (crate) restriction was advisory only — external deserialization
already worked via the derived Deserialize, so making it pub doesn't
widen the actual surface, just makes it honest.
Lib gate: 1314 passed, no regressions.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
