PR 2/10 — Port shared models and SCSS - #754

Summary

Part of the Angular -> React migration chain; based on devin-09.08.2026-devanshi/scaffold-react-vite-app. Types-and-styles only — no components or logic.

• src/app/shared/models/*.ts -> react-app/src/models/, converted from classes to interfaces (they were used purely as types); FeedType stays a string-literal union. Field names/types unchanged, except Story gains the optional content and text fields the Angular templates read (item.content / item.text), and fields the HN API omits are optional (Story.url|domain|comments|poll|poll_votes_count|deleted|dead, Comment.deleted, User.about). Story.time_ago: number is kept verbatim from the Angular model even though the API returns a string, to avoid behavioural drift in this PR.
• _media.scss, _theme_variables.scss, _themes.scss copied unchanged into react-app/src/styles/ (their relative @imports still resolve). src/styles.scss -> react-app/src/styles/styles.scss with the import repointed to ./themes and the Angular-only host selectors swapped for the React root:

-@import "./app/shared/scss/themes";
+@import "./themes";
-app-root:empty + .app-loader { ... }
+#root:empty + .app-loader { ... }

• main.tsx imports ./styles/styles.scss globally (not CSS Modules, so theme class names stay global).

Proposed fixes

• vite.config.ts: test.passWithNoTests: true — the scaffold has a vitest setup but no spec files yet, so npm test exited 1 on the base branch; later PRs in the chain add real tests.
• Sass emits deprecation warnings for @import / darken() from the copied theme files; left as-is to keep the copy faithful, worth a follow-up to move to @use / color.adjust.

Verified in react-app/: npm run typecheck, npm run lint, npm test, npm run build all pass.

Link to Devin session: https://app.devin.ai/sessions/09c4d1e3aa4f4f928ab6f6b0ac47ee03
Open in Devin Desktop: https://app.devin.ai/desktop/session/09c4d1e3aa4f4f928ab6f6b0ac47ee03?variant=devin
Requested by: @devanshi-gpta