mAi: #101 - add missing event.title.approval_decided + member_role_changed i18n

The FilterBar project_event_kind chip cluster (frontend/src/client/
filter-bar/axes.ts) renders one chip per KnownProjectEventKind via
tDyn(`event.title.${kind}`), which falls back to the raw key when the
catalog is missing the entry. Two kinds were uncovered:

  - approval_decided      → "Genehmigung entschieden" / "Approval decided"
  - member_role_changed   → "Teamrolle geändert"      / "Team role changed"

Both are now present in DE + EN. i18n-keys.ts regenerated by the build.

Audit of KnownProjectEventKinds (filter_spec.go:200) vs. the catalog —
all 18 kinds now have DE + EN labels.

frontend/src/client/i18n.ts

@@ -1117,6 +1117,10 @@ const translations: Record<Lang, Record<string, string>> = {
     "event.title.appointment_updated": "Termin ge\u00e4ndert",
     "event.title.appointment_deleted": "Termin gel\u00f6scht",
     "event.title.appointment_project_changed": "Termin verschoben",
+    // Umbrella audit kind + admin churn surfaced by the FilterBar
+    // project_event_kind chip cluster (KnownProjectEventKinds).
+    "event.title.approval_decided": "Genehmigung entschieden",
+    "event.title.member_role_changed": "Teamrolle ge\u00e4ndert",
     // 4-eye approval lifecycle (t-paliad-138). Verlauf renders these as
     // a paired card with the original lifecycle event (e.g.
     // "Frist angelegt" + "Genehmigung erteilt von Bert").
@@ -4143,6 +4147,10 @@ const translations: Record<Lang, Record<string, string>> = {
     "event.title.appointment_updated": "Appointment updated",
     "event.title.appointment_deleted": "Appointment deleted",
     "event.title.appointment_project_changed": "Appointment moved",
+    // Umbrella audit kind + admin churn surfaced by the FilterBar
+    // project_event_kind chip cluster (KnownProjectEventKinds).
+    "event.title.approval_decided": "Approval decided",
+    "event.title.member_role_changed": "Team role changed",
     // 4-eye approval lifecycle (t-paliad-138).
     "event.title.deadline_approval_requested": "Approval requested",
     "event.title.deadline_approval_approved": "Approval granted",

frontend/src/i18n-keys.ts

@@ -1604,6 +1604,7 @@ export type I18nKey =
   | "event.title.appointment_deleted"
   | "event.title.appointment_project_changed"
   | "event.title.appointment_updated"
+  | "event.title.approval_decided"
   | "event.title.checklist_created"
   | "event.title.checklist_deleted"
   | "event.title.checklist_linked"
@@ -1622,6 +1623,7 @@ export type I18nKey =
   | "event.title.deadline_reopened"
   | "event.title.deadline_updated"
   | "event.title.deadlines_imported"
+  | "event.title.member_role_changed"
   | "event.title.note_created"
   | "event.title.our_side_changed"
   | "event.title.project_archived"