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/application/src/error.rs

@@ -6,7 +6,8 @@
 //! with one error shape when building its `ErrorDTO`.
 
 use domain::ports::{
-    FsError, GitError, ProcessError, PtyError, RemoteError, RuntimeError, StoreError,
+    EmbedderError, FsError, GitError, MemoryError, ProcessError, PtyError, RemoteError,
+    RuntimeError, StoreError,
 };
 
 /// Errors surfaced by application use cases.
@@ -84,6 +85,26 @@ impl From<StoreError> for AppError {
     }
 }
 
+impl From<MemoryError> for AppError {
+    fn from(e: MemoryError) -> Self {
+        match e {
+            MemoryError::NotFound => Self::NotFound("memory note".to_owned()),
+            MemoryError::Frontmatter(m) => Self::Invalid(m),
+            other => Self::Store(other.to_string()),
+        }
+    }
+}
+
+impl From<EmbedderError> for AppError {
+    /// Maps to [`AppError::Store`] — an embedder is a *derived* recall detail; its
+    /// failure must degrade the recall (fallback to naïve), never fail hard. This
+    /// mapping exists for completeness; recall adapters degrade *before* an
+    /// embedder error ever reaches a use case.
+    fn from(e: EmbedderError) -> Self {
+        Self::Store(e.to_string())
+    }
+}
+
 impl From<PtyError> for AppError {
     fn from(e: PtyError) -> Self {
         Self::Process(e.to_string())