# ALPHA50.9.20 — Living Chat Mandala n-gram profile

## Scope
Add non-semantic 2-gram/3-gram sequence statistics so the color character of a Living Chat Mandala depends on recurring character combinations as well as individual character frequencies.

## Privacy
- N-grams are generated only in memory.
- Each n-gram is converted to a bounded hash bucket before persistence.
- Literal n-gram/word fragments are never stored.

## Behavior
- The top character classes remain locked when profiling reaches 2,000 text symbols + 12 unique text symbols.
- The cumulative n-gram profile is refreshed after subsequent messages.
- 70% of palette weight comes from locked character frequencies and 30% from the evolving sequence profile.
- The sequence profile also affects the deterministic arrangement of colors across logical units.
- No message text is stored or rendered per message; only the aggregated state changes.

## Acceptance
- Equal character profiles with different sequence profiles produce different deterministic palette/unit mappings.
- A locked Chat Mandala changes its color arrangement when the cumulative sequence profile evolves.
- Existing structure, lifecycle, PNG, localization and privacy behavior remains intact.