fix: RTL support for timelines and header dropdown

- InteractiveTimeline: dir="ltr" on scroll area, i18n for all strings
- ArtefactVersionTimeline: text-start, ms-11 logical properties
- Header dropdown: end-0 instead of right-0, text-start on menu items
- Added 11 new timeline i18n keys (en + ar)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

client/src/components/Header.jsx

@@ -122,7 +122,7 @@ export default function Header() {
             }`}>
               {getInitials(user?.name)}
             </div>
-            <div className="text-left hidden sm:block">
+            <div className="text-start hidden sm:block">
               <p className="text-sm font-medium text-text-primary">
                 {user?.name || 'User'}
               </p>
@@ -134,7 +134,7 @@ export default function Header() {
           </button>
 
           {showDropdown && (
-            <div className="absolute right-0 top-full mt-2 w-64 bg-white rounded-xl shadow-lg border border-border overflow-hidden animate-scale-in">
+            <div className="absolute end-0 top-full mt-2 w-64 bg-white rounded-xl shadow-lg border border-border overflow-hidden animate-scale-in">
               {/* User info */}
               <div className="px-4 py-3 border-b border-border-light bg-surface-secondary">
                 <p className="text-sm font-semibold text-text-primary">{user?.name}</p>
@@ -153,7 +153,7 @@ export default function Header() {
                       setShowDropdown(false)
                       window.location.href = '/users'
                     }}
-                    className="w-full flex items-center gap-3 px-4 py-2.5 hover:bg-surface-secondary transition-colors text-left"
+                    className="w-full flex items-center gap-3 px-4 py-2.5 hover:bg-surface-secondary transition-colors text-start"
                   >
                     <Shield className="w-4 h-4 text-text-tertiary" />
                     <span className="text-sm text-text-primary">User Management</span>
@@ -162,7 +162,7 @@ export default function Header() {
 
                 <button
                   onClick={openPasswordModal}
-                  className="w-full flex items-center gap-3 px-4 py-2.5 hover:bg-surface-secondary transition-colors text-left"
+                  className="w-full flex items-center gap-3 px-4 py-2.5 hover:bg-surface-secondary transition-colors text-start"
                 >
                   <Lock className="w-4 h-4 text-text-tertiary" />
                   <span className="text-sm text-text-primary">Change Password</span>