v0.1.39

opencode + telegram: customer-ready (DIVE-45)

Two fixes that together unblock shipping opencode telegram agents to customers:

1. access.json always seeded. install_channel_for_opencode_agent previously only wrote access.json when --telegram-allowed-users was passed. The normal "provision bot, pair via first DM" flow left no file, and the bridge's loadAccess() defaults to block-everything (allowFrom:[], dmPolicy:allowlist) → the bot silently dropped every DM. Now it always seeds: dmPolicy:pairing with no allowed-users (first DM yields a pairing code), allowlist when users are given. An existing policy is never overridden.

2. install.sh stages telegram-opencode. The installer staged telegram-codex/-grok/-agy but not -opencode, so a customer box couldn't provision an opencode telegram agent at all. Added the staging block (mirrors agy); update.sh --upgrade heals existing boxes at the next nightly refresh.

Verified on a fresh Hetzner box: the smoke's new opencode-telegram regression row passes (access.json pre-seeded with dmPolicy:pairing; plugin staged).