Merge branch 'feature/issue-ticket-system' into feature/background-tasks-first-class

Intègre le système de tickets/issues V1 (validé QA vert de bout en bout,
mémoire tickets-v1-e2e-validated-qa) dans la branche des tâches de fond.
Conflits résolus : app-tauri/state.rs, domain/events.rs, domain/lib.rs, domain/ports.rs.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

crates/domain/src/ids.rs

@@ -72,6 +72,10 @@ typed_id!(
     /// Identifies a [`crate::skill::Skill`].
     SkillId
 );
+typed_id!(
+    /// Identifies a [`crate::issue::Issue`].
+    IssueId
+);
 typed_id!(
     /// Identifies a [`crate::terminal::TerminalSession`].
     SessionId