Post-JB (after SpringBreak)

Pi4 agent (cron / Forgejo webhook)
  │
  ├── telnet → Kindle (poll: awake? doc open?)
  ├── netcat → push new docs
  ├── trigger KOReader to open latest
  └── log: what was read, when

Kindle PW5 (jailbroken)
  ├── telnetd (scriptlet: Start telnet)
  ├── KOReader (scriptlet-installed, handles MD/EPUB/PDF/TXT)
  ├── ads disabled (scriptlet: Disable ADs)
  ├── OTA permanently blocked (KUAL: renameotabin)
  └── KOReader launcher (scriptlet, asap mode)