feat(infra,app): store FS live-state + use cases (LS2)

Adapter d'infrastructure et use cases applicatifs du live-state agent.
- `FsLiveStateStore` : persistance fichier avec écriture atomique
  (write-temp + rename) pour éviter tout snapshot partiel/corrompu.
- Use cases `UpdateLiveState` / `GetLiveStateLean` + DTO « lean » (vue
  allégée, bornée pour l'injection/affichage).
- Rétention bornée côté store (TTL + max_n) au-dessus des invariants
  domaine (keyed last-writer-wins, prune).
- Garde-fou versionné : `.gitignore` exclut `.ideai/live-state.json`
  (snapshot runtime reconstruit, non versionné — contrairement à
  `.ideai/memory/`).

cargo test -p infrastructure -p application : 0 échec (dont 5 tests
live_state_store) ; cargo fmt --all --check : exit 0.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.gitignore

@@ -40,6 +40,9 @@ frontend/coverage/
 # Runtime file-protocol orchestration requests/responses — transient I/O, not
 # durable project state (curation .ideai §chantier secondaire).
 .ideai/requests/
+# Volatile agent live-state snapshot ("who is doing what right now", lot LS2):
+# rebuilt at runtime, keyed last-writer-wins — not versioned (unlike .ideai/memory/).
+.ideai/live-state.json
 
 # ─── Editors / OS ───────────────────────────────────────────────────────────
 .idea/

crates/application/src/lib.rs

@@ -122,7 +122,8 @@ pub use window::{MoveTabToNewWindow, MoveTabToNewWindowInput, MoveTabToNewWindow
 pub use workstate::{
     AgentTicketState, AgentWorkState, AttachLiveAgent, AttachLiveAgentInput, AttachLiveAgentOutput,
     ConversationLogProvider, ConversationPreviewStatus, ConversationTurnWorkPreview,
-    ConversationWorkSummary, GetProjectWorkState, GetProjectWorkStateInput, LiveWorkSession,
-    ProjectWorkState, StopLiveAgent, StopLiveAgentInput, StopLiveAgentOutput, TicketWorkSource,
-    TicketWorkStatus,
+    ConversationWorkSummary, GetLiveStateLean, GetProjectWorkState, GetProjectWorkStateInput,
+    LeanLiveEntry, LeanLiveState, LiveWorkSession, ProjectWorkState, StopLiveAgent,
+    StopLiveAgentInput, StopLiveAgentOutput, TicketWorkSource, TicketWorkStatus, UpdateLiveState,
+    UpdateLiveStateInput, LIVE_STATE_MAX_ENTRIES, LIVE_STATE_TTL_MS,
 };

crates/application/src/workstate/live.rs

@@ -0,0 +1,343 @@
+//! Live-state write/read use cases (programme live-state, lot LS2).
+//!
+//! The **live-state** is the durable-but-volatile "who is doing what right now"
+//! projection: one [`LiveEntry`] per agent, persisted through the
+//! [`LiveStateStore`] port (keyed last-writer-wins, never a journal).
+//!
+//! This module owns the two use cases over that port:
+//! - [`UpdateLiveState`] — publish/replace an agent's current row (write side),
+//!   stamping `updated_at_ms` from the injected [`Clock`] and enforcing the
+//!   domain field bounds via [`LiveEntry::new`].
+//! - [`GetLiveStateLean`] — prune-on-read then return a **distilled** snapshot
+//!   ([`LeanLiveState`]) for agent context injection and the future MCP tools.
+//!
+//! ## Boundary (programme invariant)
+//!
+//! The live-state stores **only what cannot be re-derived**: an agent's declared
+//! `intent`/`progress`, its current `ticket` and its `last_delegation`. Busy
+//! state, live sessions and the delegation queue are **computed elsewhere**
+//! ([`crate::workstate::GetProjectWorkState`]) and are deliberately *not* copied
+//! here. The lean DTO is also distinct from that rich, human-facing read model.
+
+use std::sync::Arc;
+
+use serde::{Deserialize, Serialize};
+
+use domain::live_state::{LiveEntry, LiveState, WorkStatus};
+use domain::ports::{Clock, LiveStateStore};
+use domain::{AgentId, TicketId};
+
+use crate::error::AppError;
+
+/// Default TTL for a live-state row, in milliseconds: **6 hours**.
+///
+/// An entry not refreshed within this window is considered stale and pruned on
+/// the next read. Six hours comfortably spans a normal working session (an agent
+/// that has not published anything for that long is effectively offline), while
+/// still bounding the file so a forgotten/abandoned project does not accumulate
+/// dead rows indefinitely.
+pub const LIVE_STATE_TTL_MS: u64 = 6 * 60 * 60 * 1_000;
+
+/// Default cardinality bound applied after the TTL sweep: keep at most this many
+/// most-recently-updated rows.
+///
+/// A project runs a handful of agents; `64` is a generous ceiling that still
+/// absorbs transient fan-out (an orchestrator delegating to many agents at once)
+/// while keeping the snapshot small and the injected context bounded.
+pub const LIVE_STATE_MAX_ENTRIES: usize = 64;
+
+/// Input for [`UpdateLiveState::execute`] — the elements of one live-state
+/// transition. `updated_at_ms` is **not** part of the input: it is stamped by the
+/// use case from the injected [`Clock`].
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct UpdateLiveStateInput {
+    /// The agent publishing the transition (the keyed identity).
+    pub agent_id: AgentId,
+    /// The ticket it is currently handling, if any.
+    pub ticket: Option<TicketId>,
+    /// Short description of the current intent (domain-bounded on construction).
+    pub intent: String,
+    /// Coarse status at a glance.
+    pub status: WorkStatus,
+    /// Optional finer-grained progress note (domain-bounded on construction).
+    pub progress: Option<String>,
+    /// The ticket of the most recent delegation this agent issued, if any.
+    pub last_delegation: Option<TicketId>,
+}
+
+/// Publishes (inserts or replaces) an agent's live-state row.
+pub struct UpdateLiveState {
+    store: Arc<dyn LiveStateStore>,
+    clock: Arc<dyn Clock>,
+}
+
+impl UpdateLiveState {
+    /// Builds the use case from the injected store and clock ports.
+    #[must_use]
+    pub fn new(store: Arc<dyn LiveStateStore>, clock: Arc<dyn Clock>) -> Self {
+        Self { store, clock }
+    }
+
+    /// Stamps `updated_at_ms` from the clock, builds a validated [`LiveEntry`]
+    /// (applying the soft truncation / hard rejection bounds) and upserts it.
+    ///
+    /// # Errors
+    /// [`AppError::Invalid`] if a text field exceeds the domain hard threshold;
+    /// [`AppError::Store`] on a persistence failure.
+    pub async fn execute(&self, input: UpdateLiveStateInput) -> Result<(), AppError> {
+        let now_ms = u64::try_from(self.clock.now_millis()).unwrap_or(0);
+        let entry = LiveEntry::new(
+            input.agent_id,
+            input.ticket,
+            input.intent,
+            input.status,
+            input.progress,
+            input.last_delegation,
+            now_ms,
+        )
+        .map_err(|e| AppError::Invalid(e.to_string()))?;
+        self.store.upsert(entry).await?;
+        Ok(())
+    }
+}
+
+/// A single distilled live-state row for injection / MCP — the **lean** DTO,
+/// deliberately narrower than the rich human read model (no `progress` free-text,
+/// no timestamp). All free-text is already domain-bounded.
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct LeanLiveEntry {
+    /// The agent this row describes.
+    pub agent_id: AgentId,
+    /// Short description of what the agent is doing (domain-bounded).
+    pub intent: String,
+    /// Coarse status at a glance.
+    pub status: WorkStatus,
+    /// The ticket it is currently handling, if any.
+    pub ticket: Option<TicketId>,
+    /// The ticket of the most recent delegation it issued, if any.
+    pub last_delegation: Option<TicketId>,
+}
+
+impl From<LiveEntry> for LeanLiveEntry {
+    fn from(e: LiveEntry) -> Self {
+        Self {
+            agent_id: e.agent_id,
+            intent: e.intent,
+            status: e.status,
+            ticket: e.ticket,
+            last_delegation: e.last_delegation,
+        }
+    }
+}
+
+/// The distilled live-state snapshot returned by [`GetLiveStateLean`].
+#[derive(Debug, Clone, Default, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct LeanLiveState {
+    /// The current rows (already pruned), one per agent.
+    pub entries: Vec<LeanLiveEntry>,
+}
+
+impl From<LiveState> for LeanLiveState {
+    fn from(state: LiveState) -> Self {
+        Self {
+            entries: state.entries.into_iter().map(LeanLiveEntry::from).collect(),
+        }
+    }
+}
+
+/// Reads the live-state, pruning stale/excess rows first, and returns the lean
+/// snapshot.
+pub struct GetLiveStateLean {
+    store: Arc<dyn LiveStateStore>,
+    clock: Arc<dyn Clock>,
+}
+
+impl GetLiveStateLean {
+    /// Builds the use case from the injected store and clock ports.
+    #[must_use]
+    pub fn new(store: Arc<dyn LiveStateStore>, clock: Arc<dyn Clock>) -> Self {
+        Self { store, clock }
+    }
+
+    /// Applies the TTL + cardinality policy ([`LIVE_STATE_TTL_MS`],
+    /// [`LIVE_STATE_MAX_ENTRIES`]) at read time, then returns the distilled
+    /// snapshot.
+    ///
+    /// # Errors
+    /// [`AppError::Store`] on a persistence failure.
+    pub async fn execute(&self) -> Result<LeanLiveState, AppError> {
+        let now_ms = u64::try_from(self.clock.now_millis()).unwrap_or(0);
+        self.store
+            .prune(now_ms, LIVE_STATE_TTL_MS, LIVE_STATE_MAX_ENTRIES)
+            .await?;
+        let state = self.store.load().await?;
+        Ok(LeanLiveState::from(state))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    use std::sync::Mutex;
+
+    use domain::live_state::FIELD_MAX_BYTES;
+    use domain::ports::StoreError;
+
+    /// In-memory [`LiveStateStore`] double mirroring the FS adapter's pure
+    /// semantics (keyed upsert + prune), with no I/O.
+    #[derive(Default)]
+    struct InMemoryLiveStateStore {
+        state: Mutex<LiveState>,
+    }
+
+    #[async_trait::async_trait]
+    impl LiveStateStore for InMemoryLiveStateStore {
+        async fn load(&self) -> Result<LiveState, StoreError> {
+            Ok(self.state.lock().unwrap().clone())
+        }
+        async fn upsert(&self, entry: LiveEntry) -> Result<(), StoreError> {
+            self.state.lock().unwrap().upsert(entry);
+            Ok(())
+        }
+        async fn prune(&self, now_ms: u64, ttl_ms: u64, max_n: usize) -> Result<(), StoreError> {
+            self.state.lock().unwrap().prune(now_ms, ttl_ms, max_n);
+            Ok(())
+        }
+    }
+
+    /// A fixed clock returning a preset epoch-ms value.
+    struct FixedClock(i64);
+    impl Clock for FixedClock {
+        fn now_millis(&self) -> i64 {
+            self.0
+        }
+    }
+
+    fn aid(n: u128) -> AgentId {
+        AgentId::from_uuid(uuid::Uuid::from_u128(n))
+    }
+
+    #[tokio::test]
+    async fn update_stamps_clock_and_persists() {
+        let store = Arc::new(InMemoryLiveStateStore::default());
+        let clock = Arc::new(FixedClock(4_242));
+        let uc = UpdateLiveState::new(store.clone(), clock);
+
+        uc.execute(UpdateLiveStateInput {
+            agent_id: aid(1),
+            ticket: None,
+            intent: "shipping".to_owned(),
+            status: WorkStatus::Working,
+            progress: None,
+            last_delegation: None,
+        })
+        .await
+        .unwrap();
+
+        let state = store.load().await.unwrap();
+        assert_eq!(state.entries.len(), 1);
+        assert_eq!(state.entries[0].intent, "shipping");
+        assert_eq!(
+            state.entries[0].updated_at_ms, 4_242,
+            "updated_at_ms stamped from the clock"
+        );
+    }
+
+    #[tokio::test]
+    async fn update_applies_domain_bounds_truncation() {
+        let store = Arc::new(InMemoryLiveStateStore::default());
+        let uc = UpdateLiveState::new(store.clone(), Arc::new(FixedClock(1)));
+
+        let long = "x".repeat(500);
+        uc.execute(UpdateLiveStateInput {
+            agent_id: aid(1),
+            ticket: None,
+            intent: long,
+            status: WorkStatus::Working,
+            progress: None,
+            last_delegation: None,
+        })
+        .await
+        .unwrap();
+
+        let state = store.load().await.unwrap();
+        assert!(
+            state.entries[0].intent.chars().count() <= 200,
+            "soft bound truncated the over-long intent"
+        );
+    }
+
+    #[tokio::test]
+    async fn update_rejects_oversize_field() {
+        let store = Arc::new(InMemoryLiveStateStore::default());
+        let uc = UpdateLiveState::new(store, Arc::new(FixedClock(1)));
+
+        let huge = "x".repeat(FIELD_MAX_BYTES + 1);
+        let err = uc
+            .execute(UpdateLiveStateInput {
+                agent_id: aid(1),
+                ticket: None,
+                intent: huge,
+                status: WorkStatus::Working,
+                progress: None,
+                last_delegation: None,
+            })
+            .await
+            .expect_err("oversize intent must be rejected");
+        assert!(matches!(err, AppError::Invalid(_)));
+    }
+
+    #[tokio::test]
+    async fn get_lean_prunes_on_read_and_returns_lean_dto() {
+        let store = Arc::new(InMemoryLiveStateStore::default());
+        // One fresh row (now-ish) and one ancient row (well beyond the TTL).
+        let now: i64 = 10 * 60 * 60 * 1_000; // 10h in ms
+        store
+            .upsert(
+                LiveEntry::new(
+                    aid(1),
+                    None,
+                    "fresh",
+                    WorkStatus::Working,
+                    Some("detailed progress note".to_owned()),
+                    None,
+                    u64::try_from(now).unwrap(),
+                )
+                .unwrap(),
+            )
+            .await
+            .unwrap();
+        store
+            .upsert(LiveEntry::new(aid(2), None, "stale", WorkStatus::Idle, None, None, 0).unwrap())
+            .await
+            .unwrap();
+
+        let lean = GetLiveStateLean::new(store.clone(), Arc::new(FixedClock(now)))
+            .execute()
+            .await
+            .unwrap();
+
+        // The ancient row (age 10h > 6h TTL) was pruned on read.
+        assert_eq!(lean.entries.len(), 1);
+        let entry = &lean.entries[0];
+        assert_eq!(entry.agent_id, aid(1));
+        assert_eq!(entry.intent, "fresh");
+        assert_eq!(entry.status, WorkStatus::Working);
+
+        // Lean DTO is narrow: no `progress` free-text leaks through. The rich
+        // serialized form must not carry it.
+        let json = serde_json::to_string(&lean).unwrap();
+        assert!(
+            !json.contains("progress"),
+            "lean DTO drops progress: {json}"
+        );
+        assert!(!json.contains("detailed progress note"));
+        assert!(json.contains("\"agentId\""), "camelCase lean DTO");
+
+        // Prune persisted: the store no longer holds the stale row either.
+        assert_eq!(store.load().await.unwrap().entries.len(), 1);
+    }
+}

crates/application/src/workstate/mod.rs

@@ -6,11 +6,16 @@
 //! durable projection.
 
 mod actions;
+mod live;
 
 pub use actions::{
     AttachLiveAgent, AttachLiveAgentInput, AttachLiveAgentOutput, StopLiveAgent,
     StopLiveAgentInput, StopLiveAgentOutput,
 };
+pub use live::{
+    GetLiveStateLean, LeanLiveEntry, LeanLiveState, UpdateLiveState, UpdateLiveStateInput,
+    LIVE_STATE_MAX_ENTRIES, LIVE_STATE_TTL_MS,
+};
 
 use std::collections::{HashMap, HashSet};
 use std::sync::Arc;

crates/infrastructure/src/lib.rs

@@ -72,8 +72,8 @@ pub use store::{detect_ollama, HttpEmbedder, DEFAULT_LOCAL_EMBED_ENDPOINT};
 pub use store::{
     embedder_from_profile, index_token_size, onnx_model_is_cached, should_use_vector,
     AdaptiveMemoryRecall, EmbedderEnvProbe, FsEmbedderProfileStore, FsEmbedderPromptStore,
-    FsMemoryStore, FsPermissionStore, FsProfileStore, FsProjectStore, FsSkillStore,
-    FsTemplateStore, HashEmbedder, IdeaiContextStore, NaiveMemoryRecall, OnnxModelInfo,
-    StubEmbedder, VectorMemoryRecall, DEFAULT_OLLAMA_BASE_URL, ONNX_CACHE_SUBDIR,
+    FsLiveStateStore, FsMemoryStore, FsPermissionStore, FsProfileStore, FsProjectStore,
+    FsSkillStore, FsTemplateStore, HashEmbedder, IdeaiContextStore, NaiveMemoryRecall,
+    OnnxModelInfo, StubEmbedder, VectorMemoryRecall, DEFAULT_OLLAMA_BASE_URL, ONNX_CACHE_SUBDIR,
     RECOMMENDED_ONNX_MODELS, VECTOR_HTTP_ENABLED, VECTOR_ONNX_ENABLED,
 };

crates/infrastructure/src/store/live_state.rs

@@ -0,0 +1,128 @@
+//! [`FsLiveStateStore`] — l'adapter `tokio::fs` du port [`LiveStateStore`]
+//! (programme live-state, lot LS2).
+//!
+//! Le **live-state** est la projection volatile « qui fait quoi en ce moment » :
+//! une entrée [`LiveEntry`](domain::live_state::LiveEntry) par agent, sémantique
+//! *keyed last-writer-wins* (jamais un journal). On en garde **un seul** fichier
+//! par projet, à la racine du `.ideai/` :
+//!
+//! ```text
+//! <project_root>/.ideai/live-state.json
+//! ```
+//!
+//! Le format est le JSON camelCase de [`LiveState`](domain::live_state::LiveState)
+//! (dérivé serde du domaine), lisible à l'œil.
+//!
+//! ## Robustesse
+//!
+//! - **Écriture atomique** : on écrit dans `live-state.json.tmp` puis on `rename`
+//!   — un lecteur ne voit jamais de fichier à moitié écrit (le `rename` est
+//!   atomique sur le FS). Même pattern que [`FsHandoffStore`](crate::FsHandoffStore).
+//! - **Fichier absent** ⇒ [`LiveState`] vide (jamais une erreur) : c'est l'état
+//!   normal d'un projet qui n'a encore rien publié.
+//! - **Fichier présent mais illisible** (JSON corrompu/partiel) ⇒
+//!   [`StoreError::Serialization`]. Choix **aligné** sur les autres stores FS
+//!   (`FsHandoffStore`, l'`index.json` de `FsSkillStore`) : on ne panique jamais,
+//!   mais on ne masque pas non plus une corruption — l'écriture atomique rend ce
+//!   cas très improbable, et le fichier étant runtime/non-versionné, le supprimer
+//!   suffit à repartir d'un état vide.
+//!
+//! Le project root est fourni au constructeur (le port [`LiveStateStore`] n'a pas
+//! de paramètre `root` par appel, contrairement à `SkillStore`/`MemoryStore`) ;
+//! une instance sert donc **un** projet.
+
+use std::path::PathBuf;
+
+use async_trait::async_trait;
+
+use domain::live_state::{LiveEntry, LiveState};
+use domain::ports::{LiveStateStore, StoreError};
+use domain::project::ProjectPath;
+
+/// Le dossier `.ideai/` dans une racine de projet.
+const IDEAI_DIR: &str = ".ideai";
+
+/// Nom du fichier de live-state, par projet.
+const LIVE_STATE_FILE: &str = "live-state.json";
+
+/// Nom du fichier temporaire d'écriture atomique (renommé sur `live-state.json`).
+const LIVE_STATE_TMP_FILE: &str = "live-state.json.tmp";
+
+/// Adapter `tokio::fs` du store de live-state, un `live-state.json` par projet.
+///
+/// Même convention de construction que [`FsHandoffStore`](crate::FsHandoffStore) :
+/// le **project root** est fourni au constructeur, la base `<root>/.ideai` en
+/// dérive, et le fichier est créé paresseusement à la première écriture.
+pub struct FsLiveStateStore {
+    /// Racine `<project_root>/.ideai`.
+    dir: PathBuf,
+}
+
+impl FsLiveStateStore {
+    /// Construit l'adapter à partir du **project root**.
+    #[must_use]
+    pub fn new(root: &ProjectPath) -> Self {
+        let dir = PathBuf::from(root.as_str()).join(IDEAI_DIR);
+        Self { dir }
+    }
+
+    /// `<root>/.ideai/live-state.json` — le fichier cible.
+    fn path(&self) -> PathBuf {
+        self.dir.join(LIVE_STATE_FILE)
+    }
+
+    /// `<root>/.ideai/live-state.json.tmp` — le tmp d'écriture atomique.
+    fn tmp_path(&self) -> PathBuf {
+        self.dir.join(LIVE_STATE_TMP_FILE)
+    }
+
+    /// Lit l'état courant : fichier absent ⇒ état vide ; JSON corrompu ⇒ erreur.
+    async fn read_state(&self) -> Result<LiveState, StoreError> {
+        match tokio::fs::read(self.path()).await {
+            Ok(bytes) => {
+                serde_json::from_slice(&bytes).map_err(|e| StoreError::Serialization(e.to_string()))
+            }
+            // Absent ⇒ état vide (jamais une erreur).
+            Err(e) if e.kind() == std::io::ErrorKind::NotFound => Ok(LiveState::default()),
+            Err(e) => Err(StoreError::Io(e.to_string())),
+        }
+    }
+
+    /// Réécrit l'état **atomiquement** : tmp puis `rename` sur la cible.
+    async fn write_state(&self, state: &LiveState) -> Result<(), StoreError> {
+        tokio::fs::create_dir_all(&self.dir)
+            .await
+            .map_err(|e| StoreError::Io(e.to_string()))?;
+
+        let bytes = serde_json::to_vec_pretty(state)
+            .map_err(|e| StoreError::Serialization(e.to_string()))?;
+
+        let tmp = self.tmp_path();
+        tokio::fs::write(&tmp, &bytes)
+            .await
+            .map_err(|e| StoreError::Io(e.to_string()))?;
+        tokio::fs::rename(&tmp, self.path())
+            .await
+            .map_err(|e| StoreError::Io(e.to_string()))?;
+        Ok(())
+    }
+}
+
+#[async_trait]
+impl LiveStateStore for FsLiveStateStore {
+    async fn load(&self) -> Result<LiveState, StoreError> {
+        self.read_state().await
+    }
+
+    async fn upsert(&self, entry: LiveEntry) -> Result<(), StoreError> {
+        let mut state = self.read_state().await?;
+        state.upsert(entry);
+        self.write_state(&state).await
+    }
+
+    async fn prune(&self, now_ms: u64, ttl_ms: u64, max_n: usize) -> Result<(), StoreError> {
+        let mut state = self.read_state().await?;
+        state.prune(now_ms, ttl_ms, max_n);
+        self.write_state(&state).await
+    }
+}

crates/infrastructure/src/store/mod.rs

@@ -6,6 +6,7 @@
 
 mod context;
 mod embedder;
+mod live_state;
 mod memory;
 mod permission;
 mod profile;
@@ -24,6 +25,7 @@ pub use embedder::{
     HashEmbedder, OnnxModelInfo, StubEmbedder, DEFAULT_OLLAMA_BASE_URL, ONNX_CACHE_SUBDIR,
     RECOMMENDED_ONNX_MODELS, VECTOR_HTTP_ENABLED, VECTOR_ONNX_ENABLED,
 };
+pub use live_state::FsLiveStateStore;
 pub use memory::{index_token_size, FsMemoryStore, NaiveMemoryRecall};
 pub use permission::FsPermissionStore;
 pub use profile::{FsEmbedderProfileStore, FsProfileStore};

crates/infrastructure/tests/live_state_store.rs

@@ -0,0 +1,157 @@
+//! LS2 integration tests for [`FsLiveStateStore`] against a **real** temp
+//! directory (programme live-state).
+//!
+//! These lock the durable behaviour an in-memory double cannot prove:
+//! - round-trip `upsert`/`load` survives a fresh instance ("restart");
+//! - a missing file => empty `LiveState` (never an error);
+//! - the write is atomic (no `.tmp` residue left behind);
+//! - `upsert` is keyed last-writer-wins, persisted (no duplicate per agent);
+//! - `prune` (TTL + max_n) is persisted.
+//!
+//! Convention: a hand-rolled [`TempDir`] over the OS temp dir (calqué sur
+//! `conversation_log.rs`) — absolute path for `ProjectPath::new`, cleaned on drop.
+
+use std::path::PathBuf;
+
+use domain::live_state::{LiveEntry, WorkStatus};
+use domain::ports::LiveStateStore;
+use domain::project::ProjectPath;
+use domain::AgentId;
+use infrastructure::FsLiveStateStore;
+use uuid::Uuid;
+
+struct TempDir(PathBuf);
+impl TempDir {
+    fn new() -> Self {
+        let p = std::env::temp_dir().join(format!("idea-ls2-livestate-{}", Uuid::new_v4()));
+        std::fs::create_dir_all(&p).unwrap();
+        Self(p)
+    }
+    fn project_path(&self) -> ProjectPath {
+        ProjectPath::new(self.0.to_string_lossy().into_owned()).unwrap()
+    }
+    fn file_path(&self) -> PathBuf {
+        self.0.join(".ideai").join("live-state.json")
+    }
+    fn tmp_path(&self) -> PathBuf {
+        self.0.join(".ideai").join("live-state.json.tmp")
+    }
+}
+impl Drop for TempDir {
+    fn drop(&mut self) {
+        let _ = std::fs::remove_dir_all(&self.0);
+    }
+}
+
+fn aid(n: u128) -> AgentId {
+    AgentId::from_uuid(Uuid::from_u128(n))
+}
+
+fn entry(agent: u128, intent: &str, status: WorkStatus, updated_at_ms: u64) -> LiveEntry {
+    LiveEntry::new(aid(agent), None, intent, status, None, None, updated_at_ms).unwrap()
+}
+
+#[tokio::test]
+async fn missing_file_loads_empty_without_error() {
+    let tmp = TempDir::new();
+    let store = FsLiveStateStore::new(&tmp.project_path());
+
+    let state = store.load().await.unwrap();
+    assert!(state.entries.is_empty(), "no file ⇒ empty live-state");
+    // load() must not have created the file.
+    assert!(!tmp.file_path().exists(), "load does not write");
+}
+
+#[tokio::test]
+async fn upsert_round_trips_across_a_fresh_instance() {
+    let tmp = TempDir::new();
+    {
+        let store = FsLiveStateStore::new(&tmp.project_path());
+        store
+            .upsert(entry(1, "building", WorkStatus::Working, 100))
+            .await
+            .unwrap();
+    }
+    // A fresh instance on the same root relits the persisted row.
+    let store = FsLiveStateStore::new(&tmp.project_path());
+    let state = store.load().await.unwrap();
+    assert_eq!(state.entries.len(), 1);
+    assert_eq!(state.entries[0].intent, "building");
+    assert_eq!(state.entries[0].status, WorkStatus::Working);
+
+    // Persisted JSON is camelCase.
+    let raw = std::fs::read_to_string(tmp.file_path()).unwrap();
+    assert!(raw.contains("\"agentId\""), "camelCase on disk: {raw}");
+    assert!(raw.contains("\"updatedAtMs\""));
+}
+
+#[tokio::test]
+async fn write_is_atomic_no_tmp_residue() {
+    let tmp = TempDir::new();
+    let store = FsLiveStateStore::new(&tmp.project_path());
+    store
+        .upsert(entry(1, "a", WorkStatus::Working, 1))
+        .await
+        .unwrap();
+    store
+        .upsert(entry(2, "b", WorkStatus::Idle, 2))
+        .await
+        .unwrap();
+
+    assert!(tmp.file_path().exists(), "final file present");
+    assert!(
+        !tmp.tmp_path().exists(),
+        "tmp file must be renamed away, not left behind"
+    );
+}
+
+#[tokio::test]
+async fn upsert_is_last_writer_wins_persisted() {
+    let tmp = TempDir::new();
+    let store = FsLiveStateStore::new(&tmp.project_path());
+
+    store
+        .upsert(entry(1, "first", WorkStatus::Working, 1))
+        .await
+        .unwrap();
+    store
+        .upsert(entry(1, "second", WorkStatus::Blocked, 2))
+        .await
+        .unwrap();
+
+    let state = store.load().await.unwrap();
+    assert_eq!(state.entries.len(), 1, "same agent ⇒ one row, no duplicate");
+    assert_eq!(state.entries[0].intent, "second");
+    assert_eq!(state.entries[0].status, WorkStatus::Blocked);
+}
+
+#[tokio::test]
+async fn prune_ttl_and_max_n_persisted() {
+    let tmp = TempDir::new();
+    let store = FsLiveStateStore::new(&tmp.project_path());
+
+    // Three rows at t=10/20/30; now=50, ttl=35 ⇒ t=10 (age 40>35) dropped,
+    // t=20 (age 30) and t=30 (age 20) kept.
+    store
+        .upsert(entry(1, "old", WorkStatus::Idle, 10))
+        .await
+        .unwrap();
+    store
+        .upsert(entry(2, "mid", WorkStatus::Working, 20))
+        .await
+        .unwrap();
+    store
+        .upsert(entry(3, "new", WorkStatus::Working, 30))
+        .await
+        .unwrap();
+
+    store.prune(50, 35, 100).await.unwrap();
+    let after_ttl = store.load().await.unwrap();
+    assert_eq!(after_ttl.entries.len(), 2, "TTL dropped the oldest");
+
+    // Now bound to 1 ⇒ keep the most recent (t=30).
+    store.prune(50, 35, 1).await.unwrap();
+    let after_cap = store.load().await.unwrap();
+    assert_eq!(after_cap.entries.len(), 1);
+    assert_eq!(after_cap.entries[0].updated_at_ms, 30);
+}