Posts can now be sourced from multiple VK groups, each routed to its own
Telegram/MAX destination(s) with independent on/off switches, configured
via data/routes.json (supports // line comments). Falls back to a single
route auto-generated from the legacy VK_SOURCE/TG_CHAT_ID/MAX_CHAT_ID env
vars if routes.json doesn't exist yet, so existing deployments keep working.
Routes are processed strictly sequentially within a cycle (no concurrency)
to keep flood control on VK/TG/MAX correct, since bot tokens are shared
across routes. DB schema gains route_id in the posts uniqueness key so the
same VK donor can safely feed multiple routes without status collisions.
Also removes the trailing-hashtag-stripping logic in text_formatter, which
was silently deleting VK posts' own hashtags whenever COMMON_TAGS wasn't
configured (it always wasn't) - posts are now forwarded unchanged.
exostring