feat(memory): système de mémoire projet model-agnostic (L14, LOT A+B+C)

Base de connaissance persistante par projet, indépendante de tout modèle/CLU
et de git. Cadrage archi en §14.5 (ARCHITECTURE.md), cycle Archi→Dev→Test.

LOT A — étage 1 (.md, source de vérité)
  - domaine: entité Memory (+ MemorySlug, MemoryType, MemoryFrontmatter,
    MemoryLink, MemoryIndexEntry), liens [[slug]], index MEMORY.md dérivé
  - port MemoryStore + MemoryError, adapter FsMemoryStore (.ideai/memory/)
  - application: 7 use cases (Create/Update/List/Get/Delete/ReadIndex/
    ResolveLinks), From<MemoryError> for AppError
  - app-tauri: commandes + DTO, events MemorySaved/MemoryDeleted
  - suppression de la variante morte DomainError::MalformedFrontmatter

LOT B — rappel adaptatif (étage 1)
  - port MemoryRecall + MemoryQuery, adapter NaiveMemoryRecall (troncature
    au budget de tokens, court-circuit budget-0), use case RecallMemory

LOT C — étage 2 vectoriel (structure complète, zéro dépendance lourde)
  - port Embedder + EmbedderError, profils déclaratifs EmbedderProfile/
    EmbedderStrategy (embedder.json)
  - VectorMemoryRecall (cosinus, cache .ideai/memory/.index/ gitignoré)
  - AdaptiveMemoryRecall (bascule pure should_use_vector), défaut none
  - HashEmbedder (déterministe, tests), StubEmbedder (onnx/server/api)

Tests: 57 binaires verts, build + clippy --workspace sans warning.

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

crates/domain/src/events.rs

@@ -2,6 +2,7 @@
 //! presentation layer (ARCHITECTURE §3.2).
 
 use crate::ids::{AgentId, ProjectId, SessionId, SkillId, TemplateId};
+use crate::memory::MemorySlug;
 use crate::template::TemplateVersion;
 
 /// Events emitted by the domain/application as state changes occur.
@@ -90,6 +91,21 @@ pub enum DomainEvent {
         /// Whether IdeA handled it successfully.
         ok: bool,
     },
+    /// A memory note was created or updated (`.md` written, index upserted).
+    MemorySaved {
+        /// The saved note's slug.
+        slug: MemorySlug,
+    },
+    /// A memory note was deleted.
+    MemoryDeleted {
+        /// The deleted note's slug.
+        slug: MemorySlug,
+    },
+    /// The aggregated `MEMORY.md` index was rebuilt for a project.
+    MemoryIndexRebuilt {
+        /// The project whose index was rebuilt.
+        project_id: ProjectId,
+    },
     /// Raw PTY output (usually routed to a dedicated channel, not this bus).
     PtyOutput {
         /// The session.