chore(wip): checkpoint P8/C avant chantier Codex inter-agents

Sauvegarde de l'arbre de travail en cours (persistance P8, conversations
C-series, write-portal frontend, médiation d'entrée) avant d'attaquer le
support de la délégation inter-agents pour les profils Codex.

Le round-trip inter-agent question/réponse est couvert sans tokens par
les tests loopback existants (state::mcp_e2e_loopback_tests).

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

crates/app-tauri/src/events.rs

@@ -56,6 +56,26 @@ pub enum DomainEventDto {
         /// `true` when a turn is in flight, `false` when idle.
         busy: bool,
     },
+    /// A delegation is ready to be injected into the agent's **native terminal**
+    /// (ARCHITECTURE §20). The frontend write-portal writes `text` + `submitSequence`
+    /// (default `"\r"`) after `submitDelayMs` (default ~60) once the human line is empty,
+    /// then acks via the `delegation_delivered` command. The backend no longer PTY-writes
+    /// the turn.
+    #[serde(rename_all = "camelCase")]
+    DelegationReady {
+        /// Target agent id (UUID string).
+        agent_id: String,
+        /// Mailbox ticket id (UUID string) to ack back via `delegation_delivered`.
+        ticket: String,
+        /// Task text to inject (written without a trailing newline by the portal).
+        text: String,
+        /// Profile's submit sequence; `null` ⇒ the front applies its default (`"\r"`).
+        #[serde(skip_serializing_if = "Option::is_none")]
+        submit_sequence: Option<String>,
+        /// Profile's submit delay in ms; `null` ⇒ the front default (~60 ms).
+        #[serde(skip_serializing_if = "Option::is_none")]
+        submit_delay_ms: Option<u32>,
+    },
     /// A target agent produced a synchronous reply to an inter-agent `ask` (§17.4).
     #[serde(rename_all = "camelCase")]
     AgentReplied {
@@ -225,6 +245,19 @@ impl From<&DomainEvent> for DomainEventDto {
                 agent_id: agent_id.to_string(),
                 busy: *busy,
             },
+            DomainEvent::DelegationReady {
+                agent_id,
+                ticket,
+                text,
+                submit_sequence,
+                submit_delay_ms,
+            } => Self::DelegationReady {
+                agent_id: agent_id.to_string(),
+                ticket: ticket.to_string(),
+                text: text.clone(),
+                submit_sequence: submit_sequence.clone(),
+                submit_delay_ms: *submit_delay_ms,
+            },
             DomainEvent::AgentReplied {
                 agent_id,
                 reply_len,