Preserve editor line breaks in the teleprompter (opt-out setting)

[mama-samba-braima]

What & why

The teleprompter flattens every line break in your script into a single space and then reflows the words purely by the container width. So no matter how you lay your script out in the editor, the on-screen prompter collapses it into one continuous block. Line breaks and paragraph gaps you deliberately typed are lost, which makes scripts with short lines, stanzas, or beats hard to follow while presenting.

The root cause is in splitTextIntoWords:

let tokens = text.replacingOccurrences(of: "\n", with: " ")  // every line break destroyed here

What this PR does

• Adds tokenizeText(), which tokenizes exactly as before but also records how many newlines preceded each word.
• Threads that metadata (lineBreaks) through OverlayContent → SpeechScrollView → WordFlowLayout, which now forces a line break at each hard newline and inserts blank lines for paragraph gaps.
• Exposes it as a new Appearance → Text Layout → "Preserve Line Breaks" toggle (on by default). When off, the prompter falls back to the previous width-only reflow, so existing behaviour is one click away.

splitTextIntoWords is unchanged for the callers that only need words (speech matching, character offsets, highlighting), so word tracking and highlighting behave identically. The change is purely additive to layout.

Applies to all four prompter surfaces: notch, floating, fullscreen, and the external-display mirror.

Behaviour

Script	Before	After (toggle on)
A\nB	A B (one line)	A / B (two lines)
A\n\nB	A B (one line)	A / (blank) / B (paragraph gap)
leading/trailing newlines	n/a	trimmed
multiple spaces / soft wrap	collapsed & width-wrapped	unchanged

Testing

• Builds clean (xcodebuild, Debug/macOS).
• Verified the tokenizer + line-break layout against 8 cases (single line, single newline, paragraph gap, leading/trailing newline trimming, multi-space collapse, triple newline → two blank lines).
• Manually tested on macOS across the notch, floating, fullscreen and external-display prompters, and toggling the setting on/off live.