Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@backend/crates/atlas-api/src/main.rs`:
- Line 51: The CHAIN_NAME env handling currently accepts an empty string; change
the retrieval logic for chain_name (the variable initialized where
std::env::var("CHAIN_NAME") is called) to treat empty or whitespace-only values
as unset by checking the env var result and falling back to "Atlas" when the
value is Err or when the Ok string is empty/only whitespace (e.g., trim and test
is_empty), so chain_name uses the default branding unless a non-empty value is
provided.

In `@docs/WHITE_LABELING.md`:
- Around line 5-13: The docs currently conflict on the default branding: the
intro claims the explorer falls back to "ev-node" branding while the CHAIN_NAME
table lists the default as "Atlas"; pick one canonical default and make the text
consistent by updating either the opening paragraph (replace "ev-node" with
"Atlas") or the table default (replace "`Atlas`" with "`ev-node`"), and ensure
the CHAIN_NAME entry and any other references to default branding in
WHITE_LABELING.md use that same value.

In `@frontend/src/context/BrandingContext.tsx`:
- Line 76: The forEach callback currently implicitly returns the result of
root.style.removeProperty(v) (vars.forEach(v => root.style.removeProperty(v));)
which violates the useIterableCallbackReturn rule; change the callback to a
block body so it returns void (e.g., vars.forEach(v => {
root.style.removeProperty(v); });) making sure the callback for vars.forEach
does not return any value.

In `@frontend/src/utils/color.ts`:
- Around line 34-40: Normalize and validate the input inside hexToRgb: trim and
ensure it starts with or without '#', accept 3- or 6-character hex forms (expand
3-char shorthand to 6-char), verify the final cleaned string is exactly 6 hex
digits (0-9a-f/A-F), and if validation fails either throw a clear error or
return a safe default RGB; then parse r/g/b with parseInt on the validated
string to avoid NaN channels. Ensure these checks are implemented in hexToRgb so
downstream CSS variable generation never receives invalid channel values.

---

Nitpick comments:
In @.env.example:
- Around line 23-27: The hex color values in the .env example (ACCENT_COLOR,
BACKGROUND_COLOR_DARK, BACKGROUND_COLOR_LIGHT, SUCCESS_COLOR, ERROR_COLOR) may
be parsed incorrectly due to the leading #; update each variable to wrap the hex
value in quotes (e.g., change ACCENT_COLOR=#dc2626 to ACCENT_COLOR="#dc2626")
and apply the same quoting to any other color vars in the file so parsers don't
treat # as a comment.