Add domain ownership of reservations and apply knowledge

PLANS.md

@@ -130,7 +130,7 @@ Each row is a delivery milestone, not a completion claim. Expand its record befo
 | 18  | Readable, complete in-app help for implemented workflows  | 17                                        | accepted      |
 | 19 | Refactoring contract, terminology and behavior map | 18 | accepted |
 | 20 | Explicit vocabulary and named operation contexts | 19 | accepted |
-| 21 | Domain ownership of reservations and apply knowledge | 20 | pending |
+| 21 | Domain ownership of reservations and apply knowledge | 20 | accepted |
 | 22 | Transactional draft editing and client creation vertical slice | 21 | pending |
 | 23 | Readable saved-state Commit and restore scenarios | 22 | pending |
 | 24 | Session-owned first delivery and password reissue scenarios | 23 | pending |
@@ -3877,7 +3877,7 @@ Accepted for presentation and synthetic fixture scope after independent review,
 
 ## Approved domain refactoring programme — milestones 19–27
 
-Status: M19–M20 accepted; M21–M27 pending. The user approved the proposed direction and requested detailed milestones on 2026-10-29. This paragraph records that plan's origin; current task progress is in the milestone records and resume point below. M18 remains accepted. These milestones preserve the approved product contract and all existing acceptance limitations, including retired/unaccepted M9 and unverified real-system paths. They do not resume VM work.
+Status: M19–M20 accepted; M21 in progress; M22–M27 pending. The user approved the proposed direction and requested detailed milestones on 2026-10-29. This paragraph records that plan's origin; current task progress is in the milestone records and resume point below. M18 remains accepted. These milestones preserve the approved product contract and all existing acceptance limitations, including retired/unaccepted M9 and unverified real-system paths. They do not resume VM work.
 
 ### Shared execution contract for M19–M27
 
@@ -3957,7 +3957,7 @@ Evidence/handoff: [M20 evidence](docs/evidence/milestone-20.md) records the clea
 
 ### Milestone 21 — Domain ownership of reservations and apply knowledge
 
-Status: pending. Prerequisite: M20 accepted.
+Status: accepted (2026-10-29T23:00:09+02:00; independent M21-R1 re-review and integrated Rust gates passed). Prerequisite: M20 accepted (2026-10-29T22:40:28+02:00). The user confirmed this session's coordinator model GPT-6-Sol/medium earlier; dispatches selected GPT-6-Luna/high explicitly. Initial tree clean at `8413b382b178991d2e1e597f1422d147f3454581`; pinned Rust/Cargo 1.97.1, rustfmt 1.9.0 and Clippy 0.1.97 available. M9 is retired/unaccepted by user direction and is not an M21 prerequisite.
 
 #### Outcome and scope
 
@@ -3965,9 +3965,9 @@ Encapsulate address retention and verification transitions without changing pers
 
 | Task | Owner | State | Bounded deliverable |
 | --- | --- | --- | --- |
-| M21.1 | implementer | pending | Encapsulated reservation rules and existing allocator integration |
+| M21.1 | implementer `/root/m21_reservations` | complete | Domain-owned committed/pending reservation sets, exact-host policy and allocator/Commit/discard integration; focused tests passed |
-| M21.2 | implementer | pending | Explicit current/historical verification transitions and caller migration |
+| M21.2 | implementer `/root/m21_reservations` | complete | Explicit current/historical verification transitions and caller migration; focused tests passed |
-| M21.3 | reviewer; repairer; coordinator | pending | Review invariant matrix, repair and RUST acceptance |
+| M21.3 | reviewer `/root/m21_reviewer`; repairer `/root/m21_repair`; coordinator | complete | M21-R1 closed on independent re-review; integrated RUST and diff check passed |
 
 1. Extract `AddressReservations` with private storage and intention-revealing operations to retain removed host addresses, restore conservative persisted reservations and expose read-only iteration/availability. Preserve conflict rejection, draft unsupported-peer reservations, Commit timing, discard behavior, IPv4/IPv6 allocation and broad-route deletion restrictions. Do not enumerate networks or infer free addresses from unavailable runtime data.
 2. Keep draft-only pending reservations distinct from committed reservations until publication. Follow M19's transition table; preserve reservations from unprojectable exact host routes, and reject unsafe broad-route deletion as before. Move policy, not filesystem/parsing/crypto, into domain.
@@ -3977,11 +3977,11 @@ Encapsulate address retention and verification transitions without changing pers
 
 #### Acceptance and validation
 
-- [ ] M21-A1: only named domain transitions can release committed reservations; backup/service/read/mismatch/persistence failures cannot release them.
+- [x] M21-A1: only named domain transitions can release committed reservations; backup/service/read/mismatch/persistence failures cannot release them.
-- [ ] M21-A2: legacy technical verification without a management snapshot, reopening and current vs historical status retain prior semantics.
+- [x] M21-A2: legacy technical verification without a management snapshot, reopening and current vs historical status retain prior semantics.
-- [ ] M21-A3: allocator, reservation, persisted round-trip and app failure tests pass; independent invariant review and RUST pass.
+- [x] M21-A3: allocator, reservation, persisted round-trip and app failure tests pass; independent invariant review and RUST pass.
 
-Focused starting commands: `cargo test --locked domain::`, `cargo test --locked persistence::`, `cargo test --locked app::`; reviewer specifically inspects reservation-release callers, not only tests. Evidence: docs/evidence/milestone-21.md. Outcome: not accepted. Handoff: M22 after acceptance.
+M21.1 and M21.2 focused checks passed. Independent reviewer found M21-R1: `commit_with_adapters` reset current apply status on unchanged Commit, changing prior Verified/Unavailable semantics. Repair removed that call and added three behavioral tests. Independent re-review closed M21-R1 with no remaining scoped finding. Final coordinator commands `cargo fmt --all -- --check`, `cargo clippy --locked --all-targets -- -D warnings`, `cargo test --locked` (399 passed, 3 ignored) and `cargo build --locked --release` all exited 0; `git diff --check` passed. [M21 evidence](docs/evidence/milestone-21.md) records final dirty source and artifact fingerprints, review and validation limits. Outcome: accepted for host/synthetic scope; stop after M21. Next action only on a separate request is M22.1; no fresh Alpine/VM result is claimed.
 
 ### Milestone 22 — Transactional draft editing and client creation vertical slice
 
@@ -4159,7 +4159,7 @@ Evidence: docs/evidence/milestone-27.md. Outcome: not accepted. Handoff: stop af
 
 ## Current progress and resume point
 
-- M20 is accepted (2026-10-29T22:40:28+02:00): renamed apply knowledge, named prepared contexts, independent M20-R1 closure and final RUST gates passed; [M20 evidence](docs/evidence/milestone-20.md) records source/artifact identity and limits. Stop after M20; M21–M27 remain pending. M19 remains accepted; M9 remains retired/unaccepted and its real-system limitations remain unchanged.
+- M21 is accepted for host/synthetic scope: domain reservation and apply-knowledge ownership, M21-R1 repair, independent re-review and required Rust gates passed. [M21 evidence](docs/evidence/milestone-21.md) records final inputs and limits. M22–M27 remain pending; M9 remains retired/unaccepted and its real-system limitations remain unchanged.
 
 - M18 was accepted on 2026-10-29: structured, accurate in-app Help, responsive wrapping and bounded scrolling passed independent R1/R2 closure, synthetic/PTY checks and pinned Rust completion gates. [M18 evidence](docs/evidence/milestone-18.md) records final inputs and limits. At that handoff, M19 had not started.
 
@@ -4188,7 +4188,7 @@ Evidence: docs/evidence/milestone-27.md. Outcome: not accepted. Handoff: stop af
 
 - Milestone 8 delivered reviewed opt-in Alpine Testcontainers coverage for real IPv4 WireGuard peers, application lifecycle, saved/runtime separation, restoration, import/reissue, backup failures and the real Rustix reader. Host gates and three fresh real-container runs passed on one stable source fingerprint; M8-A1–A10 accepted. Real IPv6 behavior is unverified by user-authorized scope.
 - Milestone 9 is retired and unaccepted: the reviewed disposable VM preparation and guarded first start did not establish Debian/systemd acceptance. The exact VM was powered off after the user stopped work. M9.2–M9.3 were not started; M9-A1–A9 are unchecked.
-- M18/M19 handoffs remain complete. M20 is accepted; the next implementation action, when separately requested, is M21.1. Keep M16 validation limitations separate from TUI evidence. Do not access production, commit, deploy or resume VM work.
+- M18–M21 handoffs remain complete. Stop after M21; begin M22.1 only on a separate request. Keep M16 validation limitations separate from TUI evidence. Do not access production, commit, deploy or resume VM work.
 
 ## Plan maintenance
 

docs/PROJECT_LAYOUT.md

@@ -28,7 +28,7 @@ src/
   main.rs                  # Startup, arguments, process exit
   lib.rs                   # Module declarations and application API
   config.rs                # Application settings and path resolution
-  domain.rs                # Clients, identities, address allocation, change states
+  domain.rs                # Clients, identities, address allocation/reservations, change states
   app.rs                   # Application operations and orchestration
   wireguard.rs             # Server configuration module boundary
   wireguard/

docs/evidence/milestone-21.md

@@ -0,0 +1,25 @@
+# Milestone 21 evidence — domain reservations and apply knowledge
+
+Run: 2026-10-29T23:00:09+02:00. Base commit: `8413b382b178991d2e1e597f1422d147f3454581` (clean at start). Final dirty source inputs: `src/domain.rs`, `src/app.rs`, and `docs/PROJECT_LAYOUT.md`; `PLANS.md` and this evidence record are coordinator documentation. `git diff -- src/domain.rs src/app.rs docs/PROJECT_LAYOUT.md | sha256sum` returned `d9056e1fd05db2425a127ac57f906333ae311bdb0f3cce13b9153f39c041c982`. `target/release/wireguard-admin` SHA-256: `60b3ad8b9c1bf2750239d3500b319cf42e5581fe027e5b6e39c8ff4115feb024`. `Cargo.toml` and `Cargo.lock` have no diff. Rust and Cargo: 1.97.1, pinned toolchain.
+
+## Implementation and invariant evidence
+
+- M21.1: `AddressReservations` owns private committed and draft-only pending host-address sets. Staging validates the entire exact `/32` or `/128` route list before mutation. The allocator sees both sets. Draft discard drops pending addresses; successful Commit promotes pending and retains addresses removed from the prior manageable saved snapshot. Persisted restoration is crate-scoped and rejects saved-client conflicts. No serialization field or version changed.
+- M21.2: private `ApplyKnowledge` owns current runtime status and optional complete last-verified management snapshot. Historical verification remains separate in persisted application history. Session open resets current knowledge to `Unknown`; technical verification may publish `Verified` with no complete management snapshot. The restart scenario prepares a cloned verified candidate, then publishes it only after internal-state installation succeeds. Only that verified transition releases committed reservations. Backup, service, read, mismatch and persistence failure paths retain reservations.
+- M21-R1: independent review found unconditional Commit demotion of `Verified` and `Unavailable` on unchanged saved client snapshots. The repair removed the extra application call; the domain Commit transition still demotes `Verified` when the saved management snapshot changes. Three behavioral app tests cover unchanged `Verified`, unchanged `Unavailable`, and changed `Verified`. The same independent reviewer re-reviewed the repair and full affected reservation/apply paths, closed M21-R1, and reported no remaining actionable finding.
+
+## Validation on integrated source
+
+| Check | Result |
+| --- | --- |
+| `cargo fmt --all -- --check` | exit 0 |
+| `cargo clippy --locked --all-targets -- -D warnings` | exit 0 |
+| `cargo test --locked` | exit 0; 399 passed, 3 ignored (opt-in Alpine drivers), 0 failed, including 2 doctests |
+| `cargo build --locked --release` | exit 0 |
+| `git diff --check` | exit 0 |
+
+Focused implementation, repair and review runs covered `domain::`, `persistence::`, `app::`, `--test commit_restore`, and `--test runtime_restart`; the final full test command supersedes those focused source results. The independent reviewer specifically inspected reservation mutation/release callers, pending/committed timing, exact-host policy, unchanged/changed Commit behavior, reopen/current versus historical state, legacy technical matching without a management snapshot, and failed verified publication.
+
+## Scope and acceptance
+
+M21-A1: passed by reviewed transition callers and synthetic failure-path tests. M21-A2: passed by legacy/reopen/history tests and the M21-R1 behavioral repair. M21-A3: passed by allocator, reservation, persistence and application tests, independent re-review and all required Rust gates. Evidence is host/synthetic. The opt-in Alpine suites and disposable systemd VM were not run for M21, and no real systemd, live VPN, production or IPv6 integration result is claimed. M9 remains retired/unaccepted. The previously recorded unprojectable-peer restore reservation gap belongs to M23 and is not represented as resolved here.

src/app.rs

@@ -81,7 +81,6 @@ pub struct Application {
     document: ConfigDocument,
     states: ClientStates,
     vault: Option<VaultBundle>,
-    draft_unsupported_reservations: BTreeSet<IpAddr>,
     historical_apply: HistoricalApplyStatus,
     verified_saved_projection: Option<SavedPeerProjection>,
     active_restart_attempt: Option<u64>,
@@ -477,7 +476,11 @@ impl fmt::Debug for Application {
             )
             .field(
                 "pending_reservation_count",
-                &self.draft_unsupported_reservations.len(),
+                &self
+                    .states
+                    .address_reservations()
+                    .pending_host_routes()
+                    .count(),
             )
             .field("initial_issue_count", &self.initial_issues.len())
             .finish()
@@ -511,7 +514,7 @@ impl Application {
         saved: SavedBytes,
         mut states: ClientStates,
     ) -> Result<Self, AppError> {
-        states.mark_runtime_unknown();
+        states.begin_runtime_session();
         let document = ConfigDocument::parse(&saved.server_config)?;
         let vault = saved
             .vault
@@ -531,7 +534,6 @@ impl Application {
             document,
             states,
             vault,
-            draft_unsupported_reservations: BTreeSet::new(),
             historical_apply,
             verified_saved_projection: None,
             active_restart_attempt: None,
@@ -633,13 +635,7 @@ impl Application {
             .into_iter()
             .collect::<Vec<_>>();
         occupied.extend(document_host_addresses(&self.document));
-        let reserved = self
+        let reserved = self.states.address_reservations().all().collect::<Vec<_>>();
-            .states
-            .reserved_addresses()
-            .iter()
-            .copied()
-            .chain(self.draft_unsupported_reservations.iter().copied())
-            .collect::<Vec<_>>();
         let availability = AddressAvailability {
             server: &server_addresses,
             occupied: &occupied,
@@ -1268,36 +1264,24 @@ impl Application {
             .peers()
             .iter()
             .any(|peer| peer.identity == Some(identity));
-        let mut additional_reservations = BTreeSet::new();
+        let mut next_states = self.states.clone();
         if saved_peer_exists && self.states.saved().get(&identity).is_none() {
             let peer = saved_document
                 .peers()
                 .iter()
                 .find(|peer| peer.identity == Some(identity))
                 .ok_or(AppError::DeletedPeerAddressUnknown)?;
-            for network in &peer.allowed_ips {
+            next_states
-                match network {
+                .stage_exact_host_routes(peer.allowed_ips.iter().copied())
-                    ipnet::IpNet::V4(network) if network.prefix_len() == 32 => {
+                .map_err(|_| AppError::DeletedPeerAddressUnknown)?;
-                        additional_reservations.insert(IpAddr::V4(network.addr()));
-                    }
-                    ipnet::IpNet::V6(network) if network.prefix_len() == 128 => {
-                        additional_reservations.insert(IpAddr::V6(network.addr()));
-                    }
-                    _ => return Err(AppError::DeletedPeerAddressUnknown),
-                }
-            }
-            if peer.allowed_ips.is_empty() || additional_reservations.is_empty() {
-                return Err(AppError::DeletedPeerAddressUnknown);
-            }
         }
         let edited = self.document.delete_client(&identity)?;
         let removed_record = match self.vault.as_mut() {
             Some(vault) => vault.remove_record(identity)?,
             None => false,
         };
-        self.states.draft_mut().remove(&identity);
+        next_states.draft_mut().remove(&identity);
-        self.draft_unsupported_reservations
+        self.states = next_states;
-            .extend(additional_reservations);
         self.document = edited;
         self.invalidate_active_issue_authorizations();
         self.initial_issues.remove(&identity);
@@ -1365,11 +1349,10 @@ impl Application {
             .map(VaultBundle::from_toml)
             .transpose()?;
         self.states.discard_draft();
-        self.draft_unsupported_reservations.clear();
         if let Some(bytes) = &self.saved.internal_state {
             PersistedState::from_toml(bytes)?.apply_to(&mut self.states)?;
         } else {
-            self.states.mark_runtime_unknown();
+            self.states.runtime_knowledge_unknown();
         }
         self.historical_apply = historical_apply_from_saved(&self.saved)?;
         self.initial_issues
@@ -1457,7 +1440,12 @@ impl Application {
         };
         self.states.draft() != self.states.saved()
             || self.document.render() != self.saved.server_config
-            || !self.draft_unsupported_reservations.is_empty()
+            || self
+                .states
+                .address_reservations()
+                .pending_host_routes()
+                .next()
+                .is_some()
             || vault_differs
     }
 
@@ -1708,7 +1696,7 @@ impl Application {
             );
         }
 
-        self.states.mark_runtime_unknown();
+        self.states.runtime_knowledge_unknown();
         let deadline = RestartDeadline::new(now(), settings.restart_timeout);
         let execution = service(&settings.systemd_unit, deadline);
         let job = execution.outcome;
@@ -1954,7 +1942,6 @@ impl Application {
         self.vault = vault;
         self.states = states;
         self.initial_issues.clear();
-        self.draft_unsupported_reservations.clear();
         self.historical_apply = HistoricalApplyStatus::Unknown;
         self.verified_saved_projection = None;
         self.active_restart_attempt = None;
@@ -1980,7 +1967,7 @@ impl Application {
             return Err(AppError::SavedGenerationChanged);
         }
         let mut next_states = self.states.clone();
-        next_states.mark_technically_applied_after_verification(observed_management_snapshot)?;
+        next_states.prepare_technically_verified_result(observed_management_snapshot)?;
         let mut persisted = match &installed.internal_state {
             Some(bytes) => PersistedState::from_toml(bytes)?,
             None => PersistedState::new(
@@ -2070,17 +2057,6 @@ impl Application {
 
         let mut next_states = self.states.clone();
         next_states.commit_draft();
-        if !self.draft_unsupported_reservations.is_empty() {
-            let reservations = next_states
-                .reserved_addresses()
-                .iter()
-                .copied()
-                .chain(self.draft_unsupported_reservations.iter().copied())
-                .map(|address| address.to_string())
-                .collect::<Vec<_>>();
-            let persisted = PersistedState::new(reservations, None)?;
-            persisted.apply_to(&mut next_states)?;
-        }
         let reservations = next_states
             .reserved_addresses()
             .iter()
@@ -2133,7 +2109,6 @@ impl Application {
 
         self.saved = proposed;
         self.states = next_states;
-        self.draft_unsupported_reservations.clear();
         self.document = ConfigDocument::parse(&self.saved.server_config)?;
         self.invalidate_active_issue_authorizations();
         promote_matching_issue_map(
@@ -3105,7 +3080,7 @@ restart_timeout_seconds = 30
             .expect("saved generation verified");
 
         let mut runtime_unknown = app.states().clone();
-        runtime_unknown.mark_runtime_unknown();
+        runtime_unknown.runtime_knowledge_unknown();
         let reopened = Application::open(app.store.clone(), runtime_unknown)
             .expect("application reopens with unknown runtime");
         let destination = reopened
@@ -3681,6 +3656,56 @@ restart_timeout_seconds = 30
         assert!(String::from_utf8_lossy(&saved.server_config).contains("# admin note\n"));
     }
 
+    #[test]
+    fn unchanged_commit_preserves_verified_apply_knowledge() {
+        let root = tempfile::tempdir().expect("temp directory");
+        let (store, states, _, _) = setup(root.path(), false);
+        let mut app = Application::open(store, states).expect("application opens");
+        let observed = app.states().saved().clone();
+        test_mark_verified(&mut app, observed, "2026-10-29T12:00:00Z".to_owned())
+            .expect("synthetic verification is published");
+        assert_eq!(app.states().applied(), &ApplyStatus::Verified);
+
+        app.commit().expect("unchanged commit completes");
+
+        assert_eq!(app.states().applied(), &ApplyStatus::Verified);
+        assert_eq!(app.states().applied_snapshot(), Some(app.states().saved()));
+    }
+
+    #[test]
+    fn unchanged_commit_preserves_unavailable_apply_knowledge() {
+        let root = tempfile::tempdir().expect("temp directory");
+        let (store, states, _, _) = setup(root.path(), false);
+        let mut app = Application::open(store, states).expect("application opens");
+        app.states.runtime_knowledge_unavailable();
+
+        app.commit().expect("unchanged commit completes");
+
+        assert_eq!(app.states().applied(), &ApplyStatus::Unavailable);
+    }
+
+    #[test]
+    fn changed_saved_snapshot_demotes_verified_apply_knowledge_on_commit() {
+        let root = tempfile::tempdir().expect("temp directory");
+        let (store, states, key, _) = setup(root.path(), false);
+        let mut app = Application::open(store, states).expect("application opens");
+        let observed = app.states().saved().clone();
+        test_mark_verified(
+            &mut app,
+            observed.clone(),
+            "2026-10-29T12:00:00Z".to_owned(),
+        )
+        .expect("synthetic verification is published");
+        app.rename_client(key, "changed saved peer")
+            .expect("peer change is staged");
+
+        app.commit().expect("changed commit completes");
+
+        assert_eq!(app.states().applied(), &ApplyStatus::Unknown);
+        assert_eq!(app.states().applied_snapshot(), Some(&observed));
+        assert_ne!(app.states().saved(), &observed);
+    }
+
     #[test]
     fn discard_restores_draft_without_writing_installed_bytes() {
         let root = tempfile::tempdir().expect("temp directory");
@@ -4976,6 +5001,18 @@ restart_timeout_seconds = 30
         assert_eq!(reopened.states().applied(), &ApplyStatus::Unknown);
     }
 
+    #[test]
+    fn open_does_not_treat_caller_seeded_verified_state_as_runtime_evidence() {
+        let root = tempfile::tempdir().expect("temp directory");
+        let (store, seeded, _, _) = setup(root.path(), false);
+        assert_eq!(seeded.applied(), &ApplyStatus::Verified);
+        let app = Application::open(store, seeded).expect("application opens");
+
+        assert_eq!(app.states().applied(), &ApplyStatus::Unknown);
+        assert!(app.states().applied_snapshot().is_some());
+        assert!(!app.saved_generation_is_verified_applied(app.saved_bytes(), app.document()));
+    }
+
     #[test]
     fn failed_verified_history_write_does_not_advance_memory_or_reopen_as_verified() {
         let root = tempfile::tempdir().expect("temp directory");

src/domain.rs

@@ -8,6 +8,70 @@ use std::str::FromStr;
 use base64::Engine as _;
 use base64::engine::general_purpose::STANDARD;
 use ipnet::{Ipv4Net, Ipv6Net};
+
+/// Committed addresses retained until verified application and exact host
+/// routes staged by a draft deletion.
+#[derive(Clone, Debug, Default, Eq, PartialEq)]
+pub struct AddressReservations {
+    committed: BTreeSet<IpAddr>,
+    pending_host_routes: BTreeSet<IpAddr>,
+}
+
+impl AddressReservations {
+    pub fn committed(&self) -> &BTreeSet<IpAddr> {
+        &self.committed
+    }
+
+    pub fn pending_host_routes(&self) -> impl Iterator<Item = IpAddr> + '_ {
+        self.pending_host_routes.iter().copied()
+    }
+
+    pub fn all(&self) -> impl Iterator<Item = IpAddr> + '_ {
+        self.committed
+            .iter()
+            .chain(&self.pending_host_routes)
+            .copied()
+    }
+
+    /// Validate the complete route list before staging any pending address.
+    pub(crate) fn stage_exact_host_routes(
+        &mut self,
+        routes: impl IntoIterator<Item = ipnet::IpNet>,
+    ) -> Result<(), DomainError> {
+        let mut addresses = BTreeSet::new();
+        let mut route_count = 0;
+        for route in routes {
+            route_count += 1;
+            match route {
+                ipnet::IpNet::V4(network) if network.prefix_len() == 32 => {
+                    addresses.insert(IpAddr::V4(network.addr()));
+                }
+                ipnet::IpNet::V6(network) if network.prefix_len() == 128 => {
+                    addresses.insert(IpAddr::V6(network.addr()));
+                }
+                _ => return Err(DomainError::UnsafeReservationRoute),
+            }
+        }
+        if route_count == 0 || addresses.is_empty() {
+            return Err(DomainError::UnsafeReservationRoute);
+        }
+        self.pending_host_routes.extend(addresses);
+        Ok(())
+    }
+
+    fn restore_committed(&mut self, reservations: impl IntoIterator<Item = IpAddr>) {
+        self.committed = reservations.into_iter().collect();
+        self.pending_host_routes.clear();
+    }
+
+    fn promote_pending(&mut self) {
+        self.committed.append(&mut self.pending_host_routes);
+    }
+
+    fn release_committed(&mut self) {
+        self.committed.clear();
+    }
+}
 use thiserror::Error;
 
 /// A WireGuard public key, decoded and validated as exactly 32 bytes.
@@ -154,18 +218,63 @@ pub enum ApplyStatus {
     Verified,
 }
 
+/// Current runtime knowledge and the optional complete management snapshot
+/// most recently verified. Historical verification time is persisted
+/// separately and never initializes this value on reopen.
+#[derive(Clone, Debug, Eq, PartialEq)]
+struct ApplyKnowledge {
+    current: ApplyStatus,
+    last_verified_snapshot: Option<Snapshot>,
+}
+
+impl ApplyKnowledge {
+    fn new(current: ApplyStatus, last_verified_snapshot: Option<Snapshot>) -> Self {
+        Self {
+            current,
+            last_verified_snapshot,
+        }
+    }
+
+    fn runtime_unknown(&mut self) {
+        self.current = ApplyStatus::Unknown;
+    }
+
+    fn runtime_unavailable(&mut self) {
+        self.current = ApplyStatus::Unavailable;
+    }
+
+    fn saved_state_changed(&mut self) {
+        self.current = ApplyStatus::Unknown;
+    }
+
+    fn new_session(&mut self) {
+        self.current = ApplyStatus::Unknown;
+    }
+
+    fn persisted_state_restored(&mut self) {
+        self.current = ApplyStatus::Unknown;
+        self.last_verified_snapshot = None;
+    }
+
+    fn prepare_verified_result(&mut self, complete_snapshot: Option<Snapshot>) {
+        self.last_verified_snapshot = complete_snapshot;
+        self.current = ApplyStatus::Verified;
+    }
+}
+
 /// Draft, saved, and last verified applied data remain independent snapshots.
 #[derive(Clone, Debug, Eq, PartialEq)]
 pub struct ClientStates {
     draft: Snapshot,
     saved: Snapshot,
-    applied_snapshot: Option<Snapshot>,
+    apply_knowledge: ApplyKnowledge,
-    applied: ApplyStatus,
+    reservations: AddressReservations,
-    reserved_addresses: BTreeSet<IpAddr>,
 }
 
 impl ClientStates {
     /// Start with a saved snapshot and an explicit initial runtime observation.
+    /// `Application::open` treats caller-provided state as untrusted runtime
+    /// evidence and resets current knowledge before exposing a session.
     pub fn new(
         saved: Snapshot,
         applied_snapshot: Option<Snapshot>,
@@ -185,9 +294,11 @@ impl ClientStates {
         Ok(Self {
             draft: saved.clone(),
             saved,
-            applied_snapshot,
+            apply_knowledge: ApplyKnowledge::new(applied, applied_snapshot),
-            applied,
+            reservations: AddressReservations {
-            reserved_addresses,
+                committed: reserved_addresses,
+                pending_host_routes: BTreeSet::new(),
+            },
         })
     }
 
@@ -200,20 +311,31 @@ impl ClientStates {
     }
 
     pub fn applied(&self) -> &ApplyStatus {
-        &self.applied
+        &self.apply_knowledge.current
     }
 
     pub fn applied_snapshot(&self) -> Option<&Snapshot> {
-        self.applied_snapshot.as_ref()
+        self.apply_knowledge.last_verified_snapshot.as_ref()
     }
 
     pub fn reserved_addresses(&self) -> &BTreeSet<IpAddr> {
-        &self.reserved_addresses
+        self.reservations.committed()
+    }
+
+    pub fn address_reservations(&self) -> &AddressReservations {
+        &self.reservations
+    }
+
+    pub(crate) fn stage_exact_host_routes(
+        &mut self,
+        routes: impl IntoIterator<Item = ipnet::IpNet>,
+    ) -> Result<(), DomainError> {
+        self.reservations.stage_exact_host_routes(routes)
     }
 
     /// Restore conservative reservations from saved metadata without asserting
     /// that the running interface matches the saved snapshot.
-    pub fn restore_persisted_reservations(
+    pub(crate) fn restore_persisted_reservations(
         &mut self,
         reservations: impl IntoIterator<Item = IpAddr>,
     ) -> Result<(), DomainError> {
@@ -224,9 +346,8 @@ impl ClientStates {
         {
             return Err(DomainError::ReservationConflictsWithSavedClient);
         }
-        self.reserved_addresses = reservations;
+        self.reservations.restore_committed(reservations);
-        self.applied_snapshot = None;
+        self.apply_knowledge.persisted_state_restored();
-        self.applied = ApplyStatus::Unknown;
         Ok(())
     }
 
@@ -237,36 +358,38 @@ impl ClientStates {
     /// Save the draft in the model only. This performs no persistence or runtime operation.
     pub fn commit_draft(&mut self) {
         let next_addresses = self.draft.addresses().collect::<BTreeSet<_>>();
-        self.reserved_addresses.extend(
+        self.reservations.committed.extend(
             self.saved
                 .addresses()
                 .filter(|address| !next_addresses.contains(address)),
         );
+        self.reservations.promote_pending();
         self.saved = self.draft.clone();
-        if self.applied == ApplyStatus::Verified
+        if self.apply_knowledge.current == ApplyStatus::Verified
-            && self.applied_snapshot.as_ref() != Some(&self.saved)
+            && self.apply_knowledge.last_verified_snapshot.as_ref() != Some(&self.saved)
         {
-            self.applied = ApplyStatus::Unknown;
+            self.apply_knowledge.saved_state_changed();
         }
     }
 
     /// Discard draft edits by returning the draft to the saved snapshot.
     pub fn discard_draft(&mut self) {
         self.draft = self.saved.clone();
+        self.reservations.pending_host_routes.clear();
     }
 
-    /// Record an applied state only when the verified observation matches saved clients.
+    /// Prepare a verified candidate only when the observation matches saved
-    pub(crate) fn mark_applied_after_verification(
+    /// clients. Callers publish the candidate after durable state installation.
+    pub(crate) fn prepare_verified_result(
         &mut self,
         observed: Snapshot,
     ) -> Result<(), DomainError> {
         if observed != self.saved {
-            self.applied = ApplyStatus::Unknown;
+            self.apply_knowledge.runtime_unknown();
             return Err(DomainError::AppliedSnapshotMismatch);
         }
-        self.applied_snapshot = Some(observed);
+        self.apply_knowledge.prepare_verified_result(Some(observed));
-        self.applied = ApplyStatus::Verified;
+        self.reservations.release_committed();
-        self.reserved_addresses.clear();
         Ok(())
     }
 
@@ -274,25 +397,28 @@ impl ClientStates {
     /// be represented by the narrower management snapshot. `None` deliberately
     /// keeps `applied_snapshot` absent instead of treating a partial snapshot as
     /// evidence that every saved peer was applied.
-    pub(crate) fn mark_technically_applied_after_verification(
+    pub(crate) fn prepare_technically_verified_result(
         &mut self,
         observed_management_snapshot: Option<Snapshot>,
     ) -> Result<(), DomainError> {
         if let Some(observed) = observed_management_snapshot {
-            return self.mark_applied_after_verification(observed);
+            return self.prepare_verified_result(observed);
         }
-        self.applied_snapshot = None;
+        self.apply_knowledge.prepare_verified_result(None);
-        self.applied = ApplyStatus::Verified;
+        self.reservations.release_committed();
-        self.reserved_addresses.clear();
         Ok(())
     }
 
-    pub fn mark_runtime_unavailable(&mut self) {
+    pub fn runtime_knowledge_unavailable(&mut self) {
-        self.applied = ApplyStatus::Unavailable;
+        self.apply_knowledge.runtime_unavailable();
     }
 
-    pub fn mark_runtime_unknown(&mut self) {
+    pub(crate) fn runtime_knowledge_unknown(&mut self) {
-        self.applied = ApplyStatus::Unknown;
+        self.apply_knowledge.runtime_unknown();
+    }
+
+    pub(crate) fn begin_runtime_session(&mut self) {
+        self.apply_knowledge.new_session();
     }
 
     /// Addresses in draft, saved, or last verified applied data cannot be reused.
@@ -301,8 +427,13 @@ impl ClientStates {
         self.draft
             .addresses()
             .chain(self.saved.addresses())
-            .chain(self.reserved_addresses.iter().copied())
+            .chain(self.reservations.all())
-            .chain(self.applied_snapshot.iter().flat_map(Snapshot::addresses))
+            .chain(
+                self.apply_knowledge
+                    .last_verified_snapshot
+                    .iter()
+                    .flat_map(Snapshot::addresses),
+            )
             .collect()
     }
 }
@@ -333,6 +464,8 @@ pub enum DomainError {
     AddressUnavailable,
     #[error("verified applied clients do not match the saved snapshot")]
     AppliedSnapshotMismatch,
+    #[error("only exact IPv4/32 or IPv6/128 host routes can be reserved")]
+    UnsafeReservationRoute,
     #[error("persisted reservation conflicts with a saved client address")]
     ReservationConflictsWithSavedClient,
 }
@@ -602,7 +735,7 @@ mod tests {
         assert_eq!(states.saved().clients().count(), 1);
         assert_eq!(states.applied(), &ApplyStatus::Unknown);
         assert_eq!(states.applied_snapshot(), Some(&saved));
-        states.mark_runtime_unavailable();
+        states.runtime_knowledge_unavailable();
         assert_eq!(states.applied(), &ApplyStatus::Unavailable);
         assert!(states.applied_snapshot().is_some());
         assert!(
@@ -634,6 +767,62 @@ mod tests {
         );
     }
 
+    #[test]
+    fn exact_host_routes_stay_pending_until_commit_and_discard_drops_them() {
+        let saved = Snapshot::new([client(1, "one", "10.0.0.2", None)]).unwrap();
+        let address = IpAddr::V4("10.0.0.9".parse().unwrap());
+        let route = "10.0.0.9/32".parse::<ipnet::IpNet>().unwrap();
+        let mut states = ClientStates::new(saved.clone(), None, ApplyStatus::Unknown).unwrap();
+
+        states.stage_exact_host_routes([route]).unwrap();
+        assert!(states.reserved_addresses().is_empty());
+        assert_eq!(
+            states
+                .address_reservations()
+                .pending_host_routes()
+                .collect::<Vec<_>>(),
+            [address]
+        );
+        assert!(states.addresses_in_use().contains(&address));
+        states.discard_draft();
+        assert!(
+            states
+                .address_reservations()
+                .pending_host_routes()
+                .next()
+                .is_none()
+        );
+        assert!(!states.addresses_in_use().contains(&address));
+
+        states.stage_exact_host_routes([route]).unwrap();
+        states.commit_draft();
+        assert!(
+            states
+                .address_reservations()
+                .pending_host_routes()
+                .next()
+                .is_none()
+        );
+        assert!(states.reserved_addresses().contains(&address));
+    }
+
+    #[test]
+    fn unsafe_route_cannot_partially_change_pending_reservations() {
+        let mut reservations = AddressReservations::default();
+        let exact = "10.0.0.9/32".parse::<ipnet::IpNet>().unwrap();
+        let broad = "10.0.0.0/24".parse::<ipnet::IpNet>().unwrap();
+        reservations.stage_exact_host_routes([exact]).unwrap();
+
+        assert_eq!(
+            reservations.stage_exact_host_routes(["10.0.0.10/32".parse().unwrap(), broad]),
+            Err(DomainError::UnsafeReservationRoute)
+        );
+        assert_eq!(
+            reservations.pending_host_routes().collect::<Vec<_>>(),
+            [IpAddr::V4("10.0.0.9".parse().unwrap())]
+        );
+    }
+
     #[test]
     fn successful_verified_apply_releases_deleted_addresses_and_mismatch_does_not() {
         let initial = Snapshot::new([client(1, "one", "10.0.0.2", None)]).unwrap();
@@ -645,7 +834,7 @@ mod tests {
         .unwrap();
         let wrong = Snapshot::new([client(2, "other", "10.0.0.3", None)]).unwrap();
         assert_eq!(
-            states.mark_applied_after_verification(wrong),
+            states.prepare_verified_result(wrong),
             Err(DomainError::AppliedSnapshotMismatch)
         );
         assert_eq!(states.applied(), &ApplyStatus::Unknown);
@@ -655,9 +844,7 @@ mod tests {
         states.commit_draft();
         assert!(!states.reserved_addresses().is_empty());
         let saved = states.saved().clone();
-        states
+        states.prepare_verified_result(saved.clone()).unwrap();
-            .mark_applied_after_verification(saved.clone())
-            .unwrap();
         assert_eq!(states.applied(), &ApplyStatus::Verified);
         assert!(states.reserved_addresses().is_empty());
         assert!(