fix(orders): price seal TTL too tight (60s) with IP binding blocks mobile users

[mostlyvirtual]

Problem

price_sealing.py:38,166: PRICE_SEAL_TTL_SECONDS = 60 with IP binding.

• 60 seconds is too tight for browse → cart → checkout flow
• Mobile users behind rotating IPs get permanent "IP address mismatch" errors
• Corporate proxies that rotate IPs between page loads block checkout

Fix

1. Increase TTL to 15-30 minutes
2. Consider removing IP binding since HMAC signature already prevents tampering
3. Add seal refresh endpoint

Files

• services/platform/apps/orders/price_sealing.py (lines 38, 166)

[b3lz3but]

Fixed by PR #148 (TTL increased to 15min, IP binding removed)

[b3lz3but]

Resolved by PR #134 (merged).