feat: Add related notes functionality with new API endpoint and frontend components, and update note search route.

notes-infra/src/link_repository.rs

@@ -65,4 +65,47 @@ impl LinkRepository for SqliteLinkRepository {
 
         Ok(())
     }
+
+    async fn get_links_for_note(&self, source_note_id: Uuid) -> DomainResult<Vec<NoteLink>> {
+        let source_str = source_note_id.to_string();
+
+        // We select links where the note is the source
+        // TODO: Should we also include links where the note is the target?
+        // For now, let's stick to outgoing links as defined by the service logic.
+        // Actually, semantic similarity is symmetric, but we only save (A -> B) if we process A.
+        // Ideally we should look for both directions or enforce symmetry.
+        // Given current implementation saves A->B when A is processed, if B is processed it saves B->A.
+        // So just querying source_note_id is fine if we assume all notes are processed.
+
+        let links = sqlx::query_as::<_, SqliteNoteLink>(
+            "SELECT * FROM note_links WHERE source_note_id = ? ORDER BY score DESC",
+        )
+        .bind(source_str)
+        .fetch_all(&self.pool)
+        .await
+        .map_err(|e| DomainError::RepositoryError(e.to_string()))?;
+
+        Ok(links.into_iter().map(NoteLink::from).collect())
+    }
+}
+
+#[derive(sqlx::FromRow)]
+struct SqliteNoteLink {
+    source_note_id: String,
+    target_note_id: String,
+    score: f32,
+    created_at: String, // Stored as ISO string
+}
+
+impl From<SqliteNoteLink> for NoteLink {
+    fn from(row: SqliteNoteLink) -> Self {
+        Self {
+            source_note_id: Uuid::parse_str(&row.source_note_id).unwrap_or_default(),
+            target_note_id: Uuid::parse_str(&row.target_note_id).unwrap_or_default(),
+            score: row.score,
+            created_at: chrono::DateTime::parse_from_rfc3339(&row.created_at)
+                .unwrap_or_default()
+                .with_timezone(&chrono::Utc),
+        }
+    }
 }