refactor: replace long arg lists with input/config structs and builder

- Thought::new_local → NewThought struct (7 args → 1)
- UserWriter::update_profile → UpdateProfileInput struct (6 args → 2)
- update_profile use case → UpdateProfileInput (8 args → 3)
- ActivityPubService::new → builder pattern (9 args → 5 required + 4 optional setters)
- accept_note → AcceptNoteInput struct (8 args → 1)
- ThoughtNote::new_public → ThoughtNoteInput struct (8 args → 1)

Remove all #[allow(clippy::too_many_arguments)] annotations.

crates/domain/src/ports.rs

@@ -12,7 +12,7 @@ use crate::{
         tag::Tag,
         thought::Thought,
         top_friend::TopFriend,
-        user::User,
+        user::{UpdateProfileInput, User},
     },
     value_objects::{
         ApiKeyId, Content, Email, NotificationId, PasswordHash, ThoughtId, UserId, Username,
@@ -69,11 +69,7 @@ pub trait UserWriter: Send + Sync {
     async fn update_profile(
         &self,
         user_id: &UserId,
-        display_name: Option<String>,
-        bio: Option<String>,
-        avatar_url: Option<String>,
-        header_url: Option<String>,
-        custom_css: Option<String>,
+        input: UpdateProfileInput,
     ) -> Result<(), DomainError>;
 }