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/components/instance/shell/right-panel/RightPanel.tsx

@@ -249,7 +249,8 @@ const RightPanel: Component<RightPanelProps> = (props) => {
     const mode = activeSplitResize()
     if (!mode) return
     event.preventDefault()
-    const delta = event.clientX - splitResizeStartX()
+    const isRtl = typeof document !== "undefined" && document.documentElement.dir === "rtl"
+    const delta = (event.clientX - splitResizeStartX()) * (isRtl ? -1 : 1)
     const next = clampSplitWidth(splitResizeStartWidth() + delta)
     if (mode === "changes") setChangesSplitWidth(next)
     else if (mode === "git-changes") setGitChangesSplitWidth(next)
@@ -272,7 +273,8 @@ const RightPanel: Component<RightPanelProps> = (props) => {
     const touch = event.touches[0]
     if (!touch) return
     event.preventDefault()
-    const delta = touch.clientX - splitResizeStartX()
+    const isRtl = typeof document !== "undefined" && document.documentElement.dir === "rtl"
+    const delta = (touch.clientX - splitResizeStartX()) * (isRtl ? -1 : 1)
     const next = clampSplitWidth(splitResizeStartWidth() + delta)
     if (mode === "changes") setChangesSplitWidth(next)
     else if (mode === "git-changes") setGitChangesSplitWidth(next)