fix(ai): correct the Context Chat embedding API key env var name

[bakiburakogun]

The Context Chat scaling section documents the embedding API key as CC_EM_API_KEY, but context_chat_backend reads CC_EM_APIKEY.

In context_chat_backend/config_parser.py:

if os.getenv('CC_EM_BASE_URL'):
    if os.getenv('CC_EM_APIKEY'):
        auth = TEmbeddingAuthApiKey(apikey=os.environ['CC_EM_APIKEY'])
    elif os.getenv('CC_EM_USERNAME') and os.getenv('CC_EM_PASSWORD'):

CC_EM_APIKEY appears four times across the repository; CC_EM_API_KEY appears nowhere. The other three names in the same sentence — CC_EM_BASE_URL, CC_EM_MODEL_NAME, CC_EM_USERNAME, CC_EM_PASSWORD — all match the code.

The failure mode is quiet: an administrator who follows the documentation sets a variable nothing reads, auth falls through to None, and the backend talks to the embedding service unauthenticated. Depending on how that service answers, the first sign of trouble is an indexing failure some distance away from the cause.

I hit this while setting up an on-premises embedding service for a Nextcloud 34 installation.

Only the documented name is changed here. If you would rather the code accept both spellings, I am happy to open that against context_chat_backend instead.

[kyteinsky]

thanks!

[kyteinsky]

will backport this after #15491 and its backports are in.

[kyteinsky]

/backport to stable35

[kyteinsky]

/backport to stable34

[kyteinsky]

/backport to stable33

[kyteinsky]

/backport to stable32