feat(i18n): Hebrew locale + full RTL support (#243)

# feat(i18n): Hebrew locale + full RTL support

## Summary

This PR adds full Hebrew (he) locale support to the UI, including a
complete translation of all user-facing strings and comprehensive RTL
layout support across all components.

## What was done

### Hebrew translation
- Full translation of all i18n message files for the `he` locale (17
translation files)
- Registered the language in the i18n system and the language picker

### RTL support
- Automatic direction detection (`dir="rtl"`) when Hebrew is selected
- Replaced physical CSS properties (`left`/`right`) with logical
equivalents (`inline-start`/`inline-end`) across the project
- Fixed resize direction, file path alignment, and textarea padding
- Fixed navigation button positioning in textarea for RTL
- Fixed scrollbar direction in RTL
- Fixed code block direction and selector alignment
- Fixed Monaco editor direction in the file viewer
- Auto-detect text direction in reasoning block (`dir="auto"` +
`unicode-bidi: plaintext`)

### Adapted components
- `session-layout` — sidebar and resize handle
- `prompt-input` — text direction and buttons
- `message-base` — message blocks and reasoning
- `message-timeline` — timeline bar
- `right-panel` — right side panel
- `tool-call` — tool call display
- `settings-screen` — settings page
- `selector` — selection component
- `instance-shell` — main shell

## New files

```
packages/ui/src/lib/i18n/messages/he/
  advancedSettings.ts
  app.ts
  commands.ts
  dialogs.ts
  filesystem.ts
  folderSelection.ts
  index.ts
  instance.ts
  loadingScreen.ts
  logs.ts
  markdown.ts
  messaging.ts
  remoteAccess.ts
  session.ts
  settings.ts
  time.ts
  toolCall.ts
```

## Suggested testing
- Switch language to Hebrew and verify all strings are translated
- Verify RTL layout is correct across all screens (session, settings,
file viewer)
- Verify that English text inside a reasoning block is displayed LTR
- Switch back to English and verify everything returns to LTR

---------

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
Co-authored-by: Shantur Rathore <i@shantur.com>

packages/ui/src/styles/panels/session-layout.css

@@ -26,10 +26,10 @@
   position: absolute;
   top: 0;
   bottom: 0;
-  left: 0;
+  inset-inline-start: 0;
   width: min(90vw, 360px);
   max-width: 360px;
-  border-right: 1px solid var(--border-base);
+  border-inline-end: 1px solid var(--border-base);
   box-shadow: var(--folder-card-shadow);
   transform: translateX(0);
   transition: transform 0.25s ease, opacity 0.2s ease;
@@ -41,6 +41,9 @@
   opacity: 0;
   pointer-events: none;
 }
+[dir="rtl"] .session-sidebar-collapsed {
+  transform: translateX(100%);
+}
 
 .session-sidebar-backdrop {
   @apply absolute inset-0;
@@ -54,7 +57,7 @@
 .session-sidebar-menu-button--floating {
   position: absolute;
   top: 1rem;
-  left: 1rem;
+  inset-inline-start: 1rem;
   z-index: 20;
 }
 
@@ -128,7 +131,7 @@ session-sidebar-controls .selector-trigger-primary {
 .mobile-fullscreen-exit-wrapper {
   position: fixed;
   top: calc(env(safe-area-inset-top, 0px) + 12px);
-  right: calc(env(safe-area-inset-right, 0px) + 12px);
+  inset-inline-end: calc(env(safe-area-inset-right, 0px) + 12px);
   z-index: 1250;
   pointer-events: none;
 }
@@ -143,11 +146,11 @@ session-sidebar-controls .selector-trigger-primary {
 }
 
 .session-resize-handle--left {
-  right: 0;
+  inset-inline-end: 0;
 }
 
 .session-resize-handle--right {
-  left: 0;
+  inset-inline-start: 0;
 }
 
 .session-resize-handle:hover {
@@ -160,14 +163,20 @@ session-sidebar-controls .selector-trigger-primary {
 }
 
 .session-resize-handle--left::before {
-  right: 0;
+  inset-inline-end: 0;
   transform: translateX(50%);
 }
+[dir="rtl"] .session-resize-handle--left::before {
+  transform: translateX(-50%);
+}
 
 .session-resize-handle--right::before {
-  left: 0;
+  inset-inline-start: 0;
   transform: translateX(-50%);
 }
+[dir="rtl"] .session-resize-handle--right::before {
+  transform: translateX(50%);
+}
 
 .session-list-header {
   @apply border-b relative;
@@ -190,14 +199,14 @@ session-sidebar-controls .selector-trigger-primary {
 }
 
 .session-item-base {
-  @apply w-full flex flex-col gap-1 px-3 py-2.5 text-left transition-colors outline-none;
+  @apply w-full flex flex-col gap-1 px-3 py-2.5 text-start transition-colors outline-none;
   font-family: var(--font-family-sans);
   font-size: var(--font-size-sm);
 }
 
 
 .session-item-base.session-item-child {
-  padding-left: 2.25rem;
+  padding-inline-start: 2.25rem;
   position: relative;
 }
 
@@ -206,7 +215,7 @@ session-sidebar-controls .selector-trigger-primary {
   position: absolute;
   top: 0;
   bottom: 0;
-  left: 1.125rem;
+  inset-inline-start: 1.125rem;
   width: 1px;
   background-color: var(--text-secondary);
   opacity: 0.95;
@@ -221,7 +230,7 @@ session-sidebar-controls .selector-trigger-primary {
   content: "";
   position: absolute;
   top: 50%;
-  left: 1.125rem;
+  inset-inline-start: 1.125rem;
   width: 0.875rem;
   height: 1px;
   background-color: var(--text-secondary);
@@ -231,11 +240,11 @@ session-sidebar-controls .selector-trigger-primary {
 }
 
 .session-item-base.session-item-border-user {
-  border-left: 4px solid var(--message-user-border);
+  border-inline-start: 4px solid var(--message-user-border);
 }
 
 .session-item-base.session-item-border-assistant {
-  border-left: 4px solid var(--message-assistant-border);
+  border-inline-start: 4px solid var(--message-assistant-border);
 }
 
 .session-item-expander {