feat(agent): orchestration v3 — surface MCP model-agnostic (M0→M4) — §14.3

Expose l'orchestration IdeA comme serveur MCP par-dessus le même
OrchestratorService::dispatch, avec repli fichier .ideai/requests pour les
CLI sans MCP. v3 réduite à la surface MCP : la messagerie inter-agents et la
corrélation requête↔réponse étaient déjà résolues par §17 (send_blocking).

- M0 capacité MCP sur le profil (McpCapability/McpConfigStrategy/McpTransport)
- M1 injection conf MCP au LaunchAgent + prose adaptée selon la surface
- M2 serveur/adapter MCP (JSON-RPC 2.0 maison ; outils idea_*) + ListAgents
- M3 câblage par projet (registre mcp_servers jumeau du watcher)
- M4 observabilité UI : OrchestratorRequestProcessed.source = file|mcp + badge

Trois portes d'entrée (fichier, MCP, UI) → un seul dispatch ; aucun nouveau
port applicatif ; MCP confiné à l'adapter infra. Tous lots verts (cycle §3).
Cadrage : .ideai/briefs/orchestration-v3-cadrage.md ; ARCHITECTURE.md §14.3.

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

crates/application/src/agent/catalogue.rs

@@ -18,7 +18,9 @@
 //! making the reference profiles addressable across runs without a registry.
 
 use domain::ids::ProfileId;
-use domain::profile::{AgentProfile, ContextInjection, StructuredAdapter};
+use domain::profile::{
+    AgentProfile, ContextInjection, McpCapability, McpConfigStrategy, McpTransport, StructuredAdapter,
+};
 
 /// A fixed UUID namespace used to derive stable ids for reference profiles.
 /// (Random-looking but constant; only its stability matters.)
@@ -57,7 +59,12 @@ pub fn reference_profiles() -> Vec<AgentProfile> {
             None,
         )
         .expect("claude reference profile is valid")
-        .with_structured_adapter(StructuredAdapter::Claude),
+        .with_structured_adapter(StructuredAdapter::Claude)
+        .with_mcp(McpCapability::new(
+            McpConfigStrategy::config_file(".mcp.json")
+                .expect(".mcp.json is a valid relative MCP config target"),
+            McpTransport::Stdio,
+        )),
         AgentProfile::new(
             reference_id("codex"),
             "OpenAI Codex CLI",
@@ -70,7 +77,12 @@ pub fn reference_profiles() -> Vec<AgentProfile> {
             None,
         )
         .expect("codex reference profile is valid")
-        .with_structured_adapter(StructuredAdapter::Codex),
+        .with_structured_adapter(StructuredAdapter::Codex)
+        .with_mcp(McpCapability::new(
+            McpConfigStrategy::config_file(".mcp.json")
+                .expect(".mcp.json is a valid relative MCP config target"),
+            McpTransport::Stdio,
+        )),
         AgentProfile::new(
             reference_id("gemini"),
             "Gemini CLI",
@@ -119,3 +131,50 @@ pub fn selectable_reference_profiles() -> Vec<AgentProfile> {
         .filter(AgentProfile::is_selectable)
         .collect()
 }
+
+#[cfg(test)]
+mod mcp_tests {
+    use super::*;
+
+    fn profile(slug: &str) -> AgentProfile {
+        let id = reference_id(slug);
+        reference_profiles()
+            .into_iter()
+            .find(|p| p.id == id)
+            .unwrap_or_else(|| panic!("reference profile `{slug}` exists"))
+    }
+
+    #[test]
+    fn claude_and_codex_expose_mcp_capability() {
+        for slug in ["claude", "codex"] {
+            let p = profile(slug);
+            assert!(
+                p.mcp.is_some(),
+                "structured profile `{slug}` must carry an MCP capability"
+            );
+        }
+    }
+
+    #[test]
+    fn claude_and_codex_mcp_use_config_file_mcp_json() {
+        for slug in ["claude", "codex"] {
+            let mcp = profile(slug).mcp.expect("mcp present");
+            assert_eq!(
+                mcp.config,
+                McpConfigStrategy::ConfigFile { target: ".mcp.json".to_owned() },
+                "profile `{slug}` should declare `.mcp.json`"
+            );
+            assert_eq!(mcp.transport, McpTransport::Stdio);
+        }
+    }
+
+    #[test]
+    fn gemini_and_aider_have_no_mcp_capability() {
+        for slug in ["gemini", "aider"] {
+            assert!(
+                profile(slug).mcp.is_none(),
+                "non-structured profile `{slug}` must NOT carry MCP (file fallback)"
+            );
+        }
+    }
+}