refactor: centralise song dict construction via _build_song_dict() (closes #454)

[mholzi]

Fixes #454 — extracts _build_song_dict(include_reveal=False) to eliminate duplicated song dict construction in PLAYING and REVEAL phases.

[gemini-code-assist]

Code Review

This pull request introduces a centralized helper method, _build_song_dict, to reduce code duplication when extracting song metadata for different game phases. The review feedback suggests improving the method's modularity and robustness by passing the song data as an explicit argument, marking it as a static method, and using a loop to simplify the assignment of localized fun fact fields.

[gemini-code-assist]

The centralized helper method _build_song_dict currently relies on the internal state self.current_song. It is more robust and modular to pass the song data as an argument. Additionally, the return type should be more specific (dict[str, Any]) to match the rest of the file's type hinting style, and the repetitive fun_fact field assignments can be simplified with a loop. Since the method doesn't depend on other instance state, it can be marked as a @staticmethod.

    @staticmethod
    def _build_song_dict(song: dict[str, Any], include_reveal: bool = False) -> dict[str, Any]:
        """Build the song info dict from song data.

        Args:
            song: The song dictionary to process.
            include_reveal: If True, include year and fun_fact fields
                            shown only during REVEAL phase.
        """
        result = {
            "artist": song.get("artist", "Unknown"),
            "title": song.get("title", "Unknown"),
            "album_art": song.get(
                "album_art", "/beatify/static/img/no-artwork.svg"
            ),
        }
        if include_reveal:
            result["year"] = song.get("year")
            for field in ["fun_fact", "fun_fact_de", "fun_fact_es", "fun_fact_fr", "fun_fact_nl"]:
                result[field] = song.get(field, "")
        return result

[gemini-code-assist]

Update the call to _build_song_dict to pass self.current_song as an argument, following the suggested signature change for better modularity.

Suggested change

	state["song"] = self._build_song_dict()
	state["song"] = self._build_song_dict(self.current_song)

[gemini-code-assist]

Update the call to _build_song_dict to pass self.current_song as an argument, following the suggested signature change for better modularity.

Suggested change

	state["song"] = self._build_song_dict(include_reveal=True)
	state["song"] = self._build_song_dict(self.current_song, include_reveal=True)

[mholzi]

LGTM — clean, correct refactor.

Fields audit:

• _build_song_dict() (PLAYING): produces artist, title, album_art with identical defaults ("Unknown", "Unknown", "/beatify/static/img/no-artwork.svg") — matches the old inline dict exactly.
• _build_song_dict(include_reveal=True) (REVEAL): adds year (no default), fun_fact + 4 locale variants (default "") — matches the old inline dict exactly.
• No fields dropped, no fields added, no default changes.

Code quality:

• Helper is well-named and scoped; include_reveal flag is a clear, minimal interface.
• Docstring is concise and useful.
• Net -20/+26 lines — the 6-line increase is the helper signature + docstring, well worth the deduplication.

✅ Would approve if this weren't my own PR.