fix(runtime): stop/restart d'agent visible robuste — kill réel, état stopped, relance froide (#196, QA verte)

Solidifie le cycle stop/restart d'un agent visible en cellule:

- terminal/registry: kill effectif de la TUI native et de la CLI custom, arrêt idempotent du live runtime (PTY + structuré), distinction nette « agent stoppé » vs « pas de session ».

- workstate + lifecycle: projection d'un état runtime explicite « stopped » (AgentRuntimeState: running/stopping/stopped/failedStart), réconcilié avec le live state; traitement des courses « agent not found ».

- relance froide via freshStart: repart de zéro sans réattacher une session morte et recharge la configuration courante de l'agent (y compris changement de modèle).

- contrat projeté côté adapters frontend (ports/domain/normalization/mock) pour la consommation UI future (#197/#198), sans surface UI ici.

Tests QA verts: workstate_actions, orchestrator_service stop_agent, agent_lifecycle (reopen/fresh_start), workstate stopped runtime state, vitest adapter stop_live_agent.

crates/application/src/workstate/mod.rs

@@ -32,7 +32,7 @@ use domain::{
 };
 
 use crate::error::AppError;
-use crate::terminal::{LiveSessionKind, LiveSessionSnapshot, LiveSessions};
+use crate::terminal::{LiveRuntimeState, LiveSessionKind, LiveSessionSnapshot, LiveSessions};
 use crate::HandoffProvider;
 
 /// Maximum length (in characters) of a derived [`AgentTicketState::task_preview`].
@@ -202,6 +202,8 @@ pub struct AgentWorkState {
     pub profile_id: ProfileId,
     /// Current live session, if the agent is live.
     pub live: Option<LiveWorkSession>,
+    /// Last known runtime lifecycle state for the agent, distinct from `live`.
+    pub runtime_state: Option<LiveRuntimeState>,
     /// Current FIFO/busy state.
     pub busy: AgentBusyState,
     /// Pending/in-progress delegation tickets, in FIFO order.
@@ -490,6 +492,10 @@ impl GetProjectWorkState {
                     session_id: snapshot.session_id,
                     kind: snapshot.kind,
                 });
+            let runtime_state = self
+                .live
+                .runtime_status_for(input.project.id, &agent.id)
+                .map(|status| status.state);
             // Tickets are crossed with the busy state: only an agent absent from
             // the manifest is dropped (this loop only visits manifest entries), so
             // the manifest boundary is naturally preserved.
@@ -510,6 +516,7 @@ impl GetProjectWorkState {
                 name: agent.name,
                 profile_id: agent.profile_id,
                 live,
+                runtime_state,
                 busy,
                 tickets,
                 background_tasks,