Function compute_backoff 

pub fn compute_backoff(
    count: u64,
    base: i64,
    max: i64,
    allow_extended: bool,
) -> i64

Compute exponential backoff duration using base-3 growth.

Returns min(base * 3^(count-1), max) for count >= 1. For count == 0 or 1 (first failure), returns base.

count	base=300s	result
0	300	300
1	300	300
2	300	900
3	300	2700
4	300	8100
5-6	14400	14400 (max, not yet extended)
7-9	86400	86400 (24h extended tier)
10+	172800	172800 (48h extended tier)

The extended tier applies when the model has hit the max cap multiple times, indicating a persistently broken model that won’t self-resolve quickly.