chore: frontend components refactoring

[anfibiacreativa]

Purpose

Refactors the frontend chat-component lit-element into several smaller lit-elements that can be used independently or removed as needed. Cleans direct DOM access as well as uses more reactive properties and state. citation previewer now supports sandbox iframe for other reference types.

Does this introduce a breaking change?

[ ] Yes
[X] No

Pull Request Type

What kind of change does this Pull Request introduce?

[ ] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[X] Refactoring (no functional changes, no api changes)
[ ] Documentation content changes
[ ] Other... Please describe:

How to Test

• Get the code

git clone [repo-address]
cd [repo-name]
git checkout [branch-name]
npm install

• Test the code

npm run test:playwright

What to Check

Verify that the following are valid

• ...

Other Information

[anfibiacreativa]

LGTM! Approved.

[shibbas]

Merging since @anfibiacreativa approved my changes to this branch.