fix: RTL support broken on chatgpt.com — responses in RTL languages render LTR

[Copilot]

ChatGPT doesn't annotate its response containers with lang or dir attributes, so GENERAL_RTL_CSS ([lang|="ar"], [dir="rtl"], etc.) never matched any element — enabling RTL for chatgpt.com had no effect.

Changes

• src/lib/css.js — adds CHATGPT_RTL_CSS targeting ChatGPT's actual response DOM: [data-message-author-role="assistant"] .markdown and its block-level descendants (p, li, h1–h6, blockquote, pre, td, th) with unicode-bidi: plaintext; text-align: start. Same bidi-algorithm approach used for YouTube — no JS text scanning needed.

• src/lib/config.js — adds CHATGPT_HOSTNAMES set (chatgpt.com, www.chatgpt.com) to identify when the site-specific CSS path applies.

• src/content.js — render() now selects CSS in three tiers: YouTube → RTL_CSS, ChatGPT → CHATGPT_RTL_CSS, everything else → GENERAL_RTL_CSS.

if (DEFAULT_RTL_HOSTNAMES.has(hostname)) {
  css = RTL_CSS;
} else if (CHATGPT_HOSTNAMES.has(hostname)) {
  css = CHATGPT_RTL_CSS;
} else {
  css = GENERAL_RTL_CSS;
}

The RTL toggle for chatgpt.com already exists in the popup and Options page — users just need to enable it.

Test plan

• Loaded extension as unpacked in Chrome
• Tested on at least 2–3 different sites
• Icon fonts (Material Icons / Font Awesome) still render correctly
• No console errors on affected pages

[Copilot]

Pull request overview

Fixes RTL rendering on chatgpt.com by adding a ChatGPT-specific CSS selector set and selecting it in the content script when the hostname matches chatgpt.com, since ChatGPT responses typically lack lang/dir attributes that the generic RTL selector relies on.

Changes:

• Add CHATGPT_RTL_CSS to target ChatGPT assistant message markdown blocks and apply unicode-bidi: plaintext + text-align: start.
• Add CHATGPT_HOSTNAMES and update the content script to choose RTL CSS in three tiers (YouTube / ChatGPT / generic).
• Update the bundled content.js output and document the fix in CHANGELOG.md.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/lib/css.js	Introduces CHATGPT_RTL_CSS targeting ChatGPT assistant markdown output.
src/lib/config.js	Adds CHATGPT_HOSTNAMES for site-specific RTL handling.
src/content.js	Selects the appropriate RTL CSS (YouTube vs ChatGPT vs generic) during render.
content.js	Updates the built/bundled content script to include the new CSS/hostname logic.
CHANGELOG.md	Adds an Unreleased changelog entry documenting the ChatGPT RTL fix.

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