fix: address review feedback on bootstrap recovery (#644)

- Fix positions() ABI selector: uint256 -> uint8 (Stage enum)
- Replace fixed sleeps with polling loops checking on-chain timestamps
- Add trailing period to 'amplitude not reached.' error hint
- Remove 'was never set' feeDestination scenario (always set by deploy)
- Clarify warning comment scope in bootstrap-common.sh

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

scripts/bootstrap-common.sh

@@ -121,7 +121,7 @@ fund_liquidity_manager() {
 
 bootstrap_vwap() {
   detect_swap_router
-  # WARNING: If the second recenter() below fails mid-sequence, the LM is left
+  # WARNING: If the second recenter() call later in this function fails mid-sequence, the LM is left
   # with positions deployed but cumulativeVolume == 0 (partial bootstrap).
   # For mainnet recovery see docs/mainnet-bootstrap.md or scripts/recover-bootstrap.sh.
   # Idempotency guard: if a previous run already bootstrapped VWAP, skip.