feat(identity): add user and fleet ownership

CHANGELOG.md

@@ -20,6 +20,17 @@ Changelog tracking starts with 0.2.0. Prior versions were not tracked.
 
 ### Added
 
+- **Astrid now has durable human and fleet ownership identities independent of
+  executable principals and capability groups.** Canonical `UserUid` and
+  `FleetUid` genesis records feed an atomically persisted ownership graph with
+  owner-safe membership changes, exclusive principal assignment, explicit
+  cross-fleet transfers, concurrent-writer protection, and fail-closed boot
+  validation. Principal deletion is rejected while a fleet assignment exists,
+  preventing identity removal from leaving a dangling ownership edge. Existing
+  native installations deterministically acquire a default user, fleet, and
+  ownership edge without changing CLI, HTTP, profile, group, or
+  `StateOwnerCodecV1` behavior. Closes #1469.
+
 - **Bulk publication reuses closure evidence earned during authoritative
   staging.** A bounded, batch-local dependency walk proves admitted owning
   closures without retaining write-history state; later publication skips only

crates/astrid-core/src/identity/mod.rs

@@ -4,11 +4,17 @@
 //! platforms, and [`FrontendLink`], a mapping from platform-specific identities
 //! to Astrid users.
 
+/// Durable human and fleet ownership identities.
+pub mod ownership;
 /// Stable principal identity.
 pub mod principal;
 /// Core identity types.
 pub mod types;
 
+pub use ownership::{
+    FleetGenesis, FleetIdentity, FleetMembership, FleetRole, FleetUid, OwnershipIdentityError,
+    PrincipalOwnership, UserGenesis, UserIdentity, UserUid,
+};
 pub use principal::{PrincipalGenesis, PrincipalIdentity, PrincipalIdentityError, PrincipalUid};
 pub use types::{AstridUserId, FrontendLink, normalize_platform};