Cryptgeon's real protocol (verified against upstream occulto/frontend/backend
source) never matched what create_note() sent: it used a SHA-256-derived key
instead of the raw one, a single-blob ciphertext instead of the delimited
AES-GCM--nonce--ciphertext format, an empty meta field instead of a JSON
string, and a hash-bang URL instead of the real /note/<id>#<key> route -
notes uploaded fine but were undecryptable in the browser.
Also adds CA_PASSPHRASE auto-detection/prompting ("" auto-detects an
encrypted CA key and prompts, "!empty"/"!ask" opt out of/force the prompt)
and an external .conf file (--config / CONFIG_PATH / <script>.conf) that can
override the SETTINGS block without editing the script.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
