feat(desktop): support RTL direction and alignment for non-LTR texts

[majidasgari]

feat(desktop): support RTL direction and alignment for non-LTR text in markdown and editor

Implement dynamic Right-to-Left (RTL) text direction and right-alignment specifically for the desktop client when rendering or typing RTL scripts (Persian, Arabic, Hebrew, etc.).

Why:

• In the desktop application, messages and query inputs containing RTL characters currently default to LTR alignment and direction, which highly degrades readability.

What:

• Guarded all RTL logic behind a window.api check (exposed by the Electron preload script) to ensure it only applies within the desktop client wrapper.
• Extended the Markdown renderer's decorate function in session-ui to dynamically apply direction: rtl and text-align: right on paragraphs (p), table cells (td, th), list items (li), and headings (h1-h6) containing RTL script characters.
• Structured Q&A tool component rendering elements in message-part.tsx are also properly styled using conditional direction and alignment attributes.
• Added a reactive isRtl memo inside the composer PromptInput component to automatically toggle the input's direction/alignment as soon as the user starts typing in an RTL language.

Impact:

• Zero side-effects on the web application or browser builds, keeping the web client's behavior and performance untouched.

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Type of change

• Bug fix
• New feature
• Refactor / code improvement
• Documentation

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Potential Duplicates Found

PR #32247 - feat(ui): full RTL support for Arabic and RTL languages

• feat(ui): full RTL support for Arabic and RTL languages #32247
• This PR appears to address comprehensive RTL support including Arabic and other RTL languages, which overlaps with the current PR's goals.

PR #32727 - fix(app): auto-detect text direction (RTL) for messages and composer

• fix(app): auto-detect text direction (RTL) for messages and composer #32727
• This PR implements auto-detection of text direction for both messages and the composer component, which directly relates to the RTL direction toggling mentioned in PR feat(desktop): support RTL direction and alignment for non-LTR texts #35635.

These PRs likely address similar or overlapping functionality for RTL text support. You may want to review their implementation approach and status to determine if PR #35635 duplicates their work or provides complementary desktop-specific enhancements.

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