refactor: group use cases into DDD bounded contexts

Flat use_cases/ (44 files) + monolithic commands.rs/queries.rs
split into diary/, movies/, watchlist/, import/, auth/, users/,
integrations/, search/, person/, federation/ — each with own
commands.rs, queries.rs, and use case modules.

Inline tests extracted to sibling tests/ dirs.

crates/application/src/import/delete_profile.rs

@@ -0,0 +1,17 @@
+use crate::{context::AppContext, import::commands::DeleteImportProfileCommand};
+use domain::{
+    errors::DomainError,
+    value_objects::{ImportProfileId, UserId},
+};
+
+pub async fn execute(ctx: &AppContext, cmd: DeleteImportProfileCommand) -> Result<(), DomainError> {
+    let user_id = UserId::from_uuid(cmd.user_id);
+    let profile_id = ImportProfileId::from_uuid(cmd.profile_id);
+
+    ctx.repos
+        .import_profile
+        .get(&profile_id, &user_id)
+        .await?
+        .ok_or_else(|| DomainError::NotFound("import profile".into()))?;
+    ctx.repos.import_profile.delete(&profile_id).await
+}