Store faces and the people they belong to

Schema v8: people, faces, face_person, face_person_rejected, and the
per-library calibration. Follows catalog.md 10.1 with two additions the
spec work turned up.

crop_px, because at the 1024px proxy tier a group shot reaches the
embedder at ~50 source pixels upsampled to 112 and a portrait at 340.
FR-CULL-9 names face size as an axis along which an uncalibrated
similarity misbehaves, so it is a stored feature rather than a UI hint.

face_person_rejected, because rejection is not the absence of an
assignment. Without it the next clustering pass re-suggests exactly the
face the user just pushed away, and the tool feels broken.

record_detections replaces rather than appends, since DetectFaces is
coalesced per image -- and carries confirmations across the replacement
by box overlap, so re-indexing with a better model cannot discard the
user's own labelling.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

core/dr-catalog/src/lib.rs

@@ -15,6 +15,7 @@
 //! - [`query`] — selectors compiled to indexed SQL, windowed for the grid
 //! - [`collections`] — the collection tree and membership the UI edits
 //! - [`keywords`] — the keyword vocabulary and what it is assigned to
+//! - [`faces`] — detected faces, the people they belong to, and who said so
 //! - [`jobs`] — the durable background work queue
 //! - [`trash`] — soft delete to a folder, then permanent delete
 //! - [`merge`] / [`sync`] — cross-device merging of collections and keywords
@@ -36,6 +37,7 @@ pub mod cache;
 pub mod collections;
 pub mod dedup;
 pub mod error;
+pub mod faces;
 pub mod jobs;
 pub mod keywords;
 pub mod merge;
@@ -51,6 +53,7 @@ pub use cache::{Budget, Cache, DEFAULT_BUDGET_BYTES};
 pub use collections::{Collection, CollectionKind, TreeRow};
 pub use dedup::{seen_by_content, seen_by_metadata, set_content_hash};
 pub use error::CatalogError;
+pub use faces::{Calibration, DetectedFace, Face, FaceId, Person, PersonId};
 pub use jobs::{Job, JobKind, Priority};
 pub use keywords::{Coverage, Keyword, KeywordId, SelectionKeyword};
 pub use merge::MergeReport;