[DO NOT MERGE] Email notification system (#4338)

* Migration

* Fixup db models

* Redis

* Stuff

* Switch PKs to BIGSERIALs, insert to notifications_deliveries when inserting notifications

* Queue, templates

* Query cache

* Fixes, fixtures

* Perf, cache template data & HTML bodies

* Notification type configuration, ResetPassword notification type

* Reset password

* Query cache

* Clippy + fmt

* Traces, fix typo, fix user email in ResetPassword

* send_email

* Models, db

* Remove dead code, adjust notification settings in migration

* Clippy fmt

* Delete dead code, fixes

* Fmt

* Update apps/labrinth/src/queue/email.rs

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Signed-off-by: François-Xavier Talbot <108630700+fetchfern@users.noreply.github.com>

* Remove old fixtures

* Unify email retry delay

* Fix type

* External notifications

* Remove `notifications_types_preference_restrictions`, as user notification preferences is out of scope for this PR

* Query cache, fmt, clippy

* Fix join in get_many_user_exposed_on_site

* Remove migration comment

* Query cache

* Update html body urls

* Remove comment

* Add paymentfailed.service variable to PaymentFailed notification variant

* Fix compile error

* Fix deleting notifications

* Update apps/labrinth/src/database/models/user_item.rs

Co-authored-by: Josiah Glosson <soujournme@gmail.com>
Signed-off-by: François-Xavier Talbot <108630700+fetchfern@users.noreply.github.com>

* Update apps/labrinth/src/database/models/user_item.rs

Co-authored-by: Josiah Glosson <soujournme@gmail.com>
Signed-off-by: François-Xavier Talbot <108630700+fetchfern@users.noreply.github.com>

* Update Cargo.toml

Co-authored-by: Josiah Glosson <soujournme@gmail.com>
Signed-off-by: François-Xavier Talbot <108630700+fetchfern@users.noreply.github.com>

* Update apps/labrinth/migrations/20250902133943_notification-extension.sql

Co-authored-by: Josiah Glosson <soujournme@gmail.com>
Signed-off-by: François-Xavier Talbot <108630700+fetchfern@users.noreply.github.com>

* Address review comments

* Fix compliation

* Update apps/labrinth/src/database/models/users_notifications_preferences_item.rs

Co-authored-by: Josiah Glosson <soujournme@gmail.com>
Signed-off-by: François-Xavier Talbot <108630700+fetchfern@users.noreply.github.com>

* Use strfmt to format emails

* Configurable Reply-To

* Configurable Reply-To

* Refactor for email background task

* Send some emails inline

* Fix account creation email check

* Revert "Use strfmt to format emails"

This reverts commit e0d6614afe.

* Reintroduce fill_template

* Set password reset email inline

* Process more emails per index

* clippy fmt

* Query cache

---------

Signed-off-by: François-Xavier Talbot <108630700+fetchfern@users.noreply.github.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: Josiah Glosson <soujournme@gmail.com>

apps/labrinth/src/auth/mod.rs

@@ -1,5 +1,4 @@
 pub mod checks;
-pub mod email;
 pub mod oauth;
 pub mod templates;
 pub mod validate;
@@ -8,9 +7,7 @@ pub use checks::{
     filter_visible_collections, filter_visible_project_ids,
     filter_visible_projects,
 };
-pub use email::send_email;
 use serde::{Deserialize, Serialize};
-// pub use pat::{generate_pat, PersonalAccessToken};
 pub use validate::{check_is_moderator_from_headers, get_user_from_headers};
 
 use crate::file_hosting::FileHostingError;
@@ -36,7 +33,7 @@ pub enum AuthenticationError {
     #[error("Error while decoding PAT: {0}")]
     Decoding(#[from] ariadne::ids::DecodingError),
     #[error("{0}")]
-    Mail(#[from] email::MailError),
+    Mail(#[from] crate::queue::email::MailError),
     #[error("Invalid Authentication Credentials")]
     InvalidCredentials,
     #[error("Authentication method was not valid")]