`src/reflection/backoff.rs` — `ExponentialBackoffRecovery`

The default recovery strategy: retry recoverable failures with exponentially growing delays.

Key items

• ExponentialBackoffRecovery::new(max_retries) — base delay 100ms, max delay 30s; builders with_base_delay, with_max_delay.
• Delay formula: base × 2^attempt, clamped to max, all saturating (no overflow at absurd attempt numbers).

Behavior notes

• Decision order: non-recoverable → Fail; past effective retries (min(strategy's, engine's max)) → Fail; High severity with a correction available → AskUser; else Retry.
• The engine’s hard ceiling (MAX_RECOVERY_ATTEMPTS = 5) overrides the strategy — the strategy is told the same number as max_attempts.
• Default construction is new(3): 3 retries, 100ms → 200ms → 400ms, cancel-aware waits.

Deep dive: Reflection.