feat(ap): ActivityPub spec compliance and profile completeness

Phase 1 — spec compliance:
- Add AS_PUBLIC constant; add to/cc fields to CreateActivity, DeleteActivity,
  UpdateActivity, AddActivity; populate on all broadcast call sites
- Add @context to outbox CreateActivity items
- Set manuallyApprovesFollowers: true to match actual Pending follow flow
- Gate PermissiveVerifier behind FEDERATION_DEBUG env var
- Add updated timestamp to Person actor JSON
- Improve actor update delivery logging

Phase 2a Batch 1 — AP layer:
- Add /inbox shared inbox route; add endpoints.sharedInbox to Person
- Paginate followers and following collections (20/page, OrderedCollectionPage)

Phase 2a Batch 2 — profile completeness:
- DB migrations: banner_path, also_known_as columns; user_profile_fields table
- ProfileField value object; UserProfileFieldsRepository port
- Banner image upload (stored via image-converter, surfaced as image in Person)
- alsoKnownAs field in Person (account migration support)
- Custom profile fields (up to 4 PropertyValue attachments in Person)
- Profile settings UI: banner preview/upload, alsoKnownAs input, fields form
- PUT /api/v1/profile/fields API endpoint

crates/adapters/sqlite/src/profile_fields.rs

@@ -0,0 +1,58 @@
+use async_trait::async_trait;
+use sqlx::SqlitePool;
+
+use domain::{
+    errors::DomainError,
+    models::ProfileField,
+    ports::UserProfileFieldsRepository,
+    value_objects::UserId,
+};
+
+pub struct SqliteProfileFieldsRepository {
+    pool: SqlitePool,
+}
+
+impl SqliteProfileFieldsRepository {
+    pub fn new(pool: SqlitePool) -> Self {
+        Self { pool }
+    }
+}
+
+#[async_trait]
+impl UserProfileFieldsRepository for SqliteProfileFieldsRepository {
+    async fn get_fields(&self, user_id: &UserId) -> Result<Vec<ProfileField>, DomainError> {
+        let id_str = user_id.value().to_string();
+        let rows = sqlx::query!(
+            "SELECT name, value FROM user_profile_fields WHERE user_id = ? ORDER BY position ASC",
+            id_str
+        )
+        .fetch_all(&self.pool)
+        .await
+        .map_err(|e| DomainError::InfrastructureError(e.to_string()))?;
+
+        Ok(rows.into_iter().map(|r| ProfileField { name: r.name, value: r.value }).collect())
+    }
+
+    async fn set_fields(&self, user_id: &UserId, fields: Vec<ProfileField>) -> Result<(), DomainError> {
+        let id_str = user_id.value().to_string();
+
+        sqlx::query!("DELETE FROM user_profile_fields WHERE user_id = ?", id_str)
+            .execute(&self.pool)
+            .await
+            .map_err(|e| DomainError::InfrastructureError(e.to_string()))?;
+
+        for (i, field) in fields.into_iter().enumerate() {
+            let id = uuid::Uuid::new_v4().to_string();
+            let position = i as i64;
+            sqlx::query!(
+                "INSERT INTO user_profile_fields (id, user_id, name, value, position) VALUES (?, ?, ?, ?, ?)",
+                id, id_str, field.name, field.value, position
+            )
+            .execute(&self.pool)
+            .await
+            .map_err(|e| DomainError::InfrastructureError(e.to_string()))?;
+        }
+
+        Ok(())
+    }
+}