fix(otbr,kan,mysql): OTBR vendor/model/socat/web binding, Kan build env vars, MySQL trixie support

- openthread-br: add socat dep for TCP adapters, add --vendor-name/--model-name
  (mandatory), bind REST API to 0.0.0.0:8081, configure otbr-web to listen on
  all interfaces, update TCP example with socat forkpty pattern
- kan: export BETTER_AUTH_SECRET and POSTGRES_URL before build (required by
  @t3-oss/env-nextjs zod validation at build time)
- mysql: remove MariaDB-on-trixie workaround (MySQL repo now has trixie packages),
  update GPG key from RPM-GPG-KEY-mysql-2023 to RPM-GPG-KEY-mysql-2025

install/kan-install.sh

@@ -31,11 +31,14 @@ fetch_and_deploy_gh_tag "kan" "kanbn/kan"
 
 msg_info "Building Application"
 cd /opt/kan
+AUTH_SECRET=$(openssl rand -base64 32)
 export NEXT_PUBLIC_USE_STANDALONE_OUTPUT=true
 export NEXT_PUBLIC_BASE_URL="http://${LOCAL_IP}:3000"
+export BETTER_AUTH_SECRET="${AUTH_SECRET}"
+export POSTGRES_URL="postgres://${PG_DB_USER}:${PG_DB_PASS}@localhost:5432/${PG_DB_NAME}"
 $STD pnpm install
 $STD pnpm build --filter=@kan/web
-unset NEXT_PUBLIC_USE_STANDALONE_OUTPUT NEXT_PUBLIC_BASE_URL
+unset NEXT_PUBLIC_USE_STANDALONE_OUTPUT NEXT_PUBLIC_BASE_URL BETTER_AUTH_SECRET POSTGRES_URL
 msg_ok "Built Application"
 
 msg_info "Setting up Standalone"
@@ -50,7 +53,6 @@ POSTGRES_URL="postgres://${PG_DB_USER}:${PG_DB_PASS}@localhost:5432/${PG_DB_NAME
 msg_ok "Ran Database Migrations"
 
 msg_info "Configuring Application"
-AUTH_SECRET=$(openssl rand -base64 32)
 cat <<EOF >/opt/kan/.env
 NEXT_PUBLIC_BASE_URL=http://${LOCAL_IP}:3000
 BETTER_AUTH_SECRET=${AUTH_SECRET}