feat(session-limits): LS6 — câblage des événements de limite vers le front

Relaie les 5 nouvelles variantes DomainEvent (AgentRateLimited, ResumeScheduled,
ResumeCancelled, Resumed, RateLimitSuspected) via leurs DTO miroirs et bras From
dans events.rs, et propage ReplyEvent::RateLimited en chunk côté chat.rs pour que
le front soit informé des suspensions/reprises de session.

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

crates/app-tauri/src/chat.rs

@@ -178,8 +178,10 @@ impl ChatBridge {
 ///
 /// Returns `None` for [`ReplyEvent::Heartbeat`]: a heartbeat is a non-terminal
 /// liveness proof (readiness/heartbeat lot 1) with **no chat content**, so it maps
-/// to no wire chunk — the pump simply skips it. Every content-bearing event still
-/// maps to exactly one chunk.
+/// to no wire chunk — the pump simply skips it. Likewise [`ReplyEvent::RateLimited`]
+/// is non-terminal and content-free (ports §21.2-T4): the UI badge comes from the
+/// `DomainEvent::AgentRateLimited` bus, not the chat stream, so it maps to `None`
+/// too. Every content-bearing event still maps to exactly one chunk.
 #[must_use]
 pub fn chunk_from_event(event: ReplyEvent) -> Option<ReplyChunk> {
     match event {
@@ -187,5 +189,6 @@ pub fn chunk_from_event(event: ReplyEvent) -> Option<ReplyChunk> {
         ReplyEvent::ToolActivity { label } => Some(ReplyChunk::ToolActivity { label }),
         ReplyEvent::Final { content } => Some(ReplyChunk::Final { content }),
         ReplyEvent::Heartbeat => None,
+        ReplyEvent::RateLimited { .. } => None,
     }
 }

crates/app-tauri/src/events.rs

@@ -205,6 +205,52 @@ pub enum DomainEventDto {
         /// Whether the in-process ONNX capability is compiled in.
         vector_onnx_enabled: bool,
     },
+    /// An agent entered a **session/rate limit** (ARCHITECTURE §21). Low-frequency,
+    /// model-agnostic badge: carries only the neutral "limited, maybe resets at T"
+    /// fact. The frontend badges "limité jusqu'à HH:MM".
+    #[serde(rename_all = "camelCase")]
+    AgentRateLimited {
+        /// Agent id (UUID string).
+        agent_id: String,
+        /// Reset instant in **epoch-milliseconds**; `null` ⇒ unknown (no auto-resume).
+        #[serde(skip_serializing_if = "Option::is_none")]
+        resets_at_ms: Option<i64>,
+    },
+    /// An **auto-resume** was armed for a rate-limited agent (ARCHITECTURE §21). The
+    /// frontend shows the countdown + the "Annuler la reprise" button (cancellable
+    /// window).
+    #[serde(rename_all = "camelCase")]
+    AgentResumeScheduled {
+        /// Agent id (UUID string).
+        agent_id: String,
+        /// Wake-up deadline in **epoch-milliseconds**.
+        fire_at_ms: i64,
+    },
+    /// An agent's **auto-resume** was **cancelled** (ARCHITECTURE §21): the user
+    /// clicked "Annuler la reprise". The frontend removes the countdown.
+    #[serde(rename_all = "camelCase")]
+    AgentResumeCancelled {
+        /// Agent id (UUID string).
+        agent_id: String,
+    },
+    /// An agent was effectively **resumed** after a limit (ARCHITECTURE §21): the
+    /// wake-up fired (or immediate resume). The frontend clears the "limited" state.
+    #[serde(rename_all = "camelCase")]
+    AgentResumed {
+        /// Agent id (UUID string).
+        agent_id: String,
+    },
+    /// **Human net (level 3)**: a session limit is **suspected** without any reliable
+    /// reset time (ARCHITECTURE §21.1). IdeA never resumes blind: this asks the front
+    /// to **prompt the user** ("limit detected but time unknown — resume at?").
+    #[serde(rename_all = "camelCase")]
+    AgentRateLimitSuspected {
+        /// Agent id (UUID string).
+        agent_id: String,
+        /// Reset instant in **epoch-milliseconds** if an estimate exists, else `null`.
+        #[serde(skip_serializing_if = "Option::is_none")]
+        resets_at_ms: Option<i64>,
+    },
     /// Raw PTY output (normally routed to a per-session channel, not here).
     #[serde(rename_all = "camelCase")]
     PtyOutput {
@@ -377,6 +423,33 @@ impl From<&DomainEvent> for DomainEventDto {
                 vector_http_enabled: *vector_http_enabled,
                 vector_onnx_enabled: *vector_onnx_enabled,
             },
+            DomainEvent::AgentRateLimited {
+                agent_id,
+                resets_at_ms,
+            } => Self::AgentRateLimited {
+                agent_id: agent_id.to_string(),
+                resets_at_ms: *resets_at_ms,
+            },
+            DomainEvent::AgentResumeScheduled {
+                agent_id,
+                fire_at_ms,
+            } => Self::AgentResumeScheduled {
+                agent_id: agent_id.to_string(),
+                fire_at_ms: *fire_at_ms,
+            },
+            DomainEvent::AgentResumeCancelled { agent_id } => Self::AgentResumeCancelled {
+                agent_id: agent_id.to_string(),
+            },
+            DomainEvent::AgentResumed { agent_id } => Self::AgentResumed {
+                agent_id: agent_id.to_string(),
+            },
+            DomainEvent::AgentRateLimitSuspected {
+                agent_id,
+                resets_at_ms,
+            } => Self::AgentRateLimitSuspected {
+                agent_id: agent_id.to_string(),
+                resets_at_ms: *resets_at_ms,
+            },
             DomainEvent::PtyOutput { session_id, bytes } => Self::PtyOutput {
                 session_id: session_id.to_string(),
                 bytes: bytes.clone(),
@@ -450,4 +523,19 @@ mod tests {
         assert_eq!(json["type"], "agentLivenessChanged");
         assert_eq!(json["liveness"], "alive");
     }
+
+    /// LS6 : un `AgentRateLimited` du domaine se relaie en DTO portant le même agent
+    /// et l'heure de reset (époche-ms), et se sérialise en `"agentRateLimited"` avec
+    /// `resetsAtMs` — le fait neutre que le front badge « limité jusqu'à HH:MM ».
+    #[test]
+    fn rate_limited_relays_to_dto_and_wire() {
+        let dto = DomainEventDto::from(&DomainEvent::AgentRateLimited {
+            agent_id: agent(11),
+            resets_at_ms: Some(1_700_000_000_000),
+        });
+        let json = serde_json::to_value(&dto).expect("serialisable");
+        assert_eq!(json["type"], "agentRateLimited");
+        assert_eq!(json["agentId"], agent(11).to_string());
+        assert_eq!(json["resetsAtMs"], 1_700_000_000_000_i64);
+    }
 }