v0.18.0:1 - scrub owner-specific hostnames, ips, usernames, names from tracked files

Replace real cluster IPs/hosts/usernames and example names with neutral
placeholders across docs, ops notes, package install text, and the offline
redaction test; delete the obsolete build-time starter prompt. Closes the
portability audit's single blocker. No runtime behavior change.

docs/AUDIO_API.md

@@ -247,8 +247,8 @@ to you, not a stranger. You also free a Sortformer speaker slot (you no longer c
 ```bash
 curl -k -X POST https://<host>/api/audio/label-merge \
   -F "mic_file=@mic.wav" -F "system_file=@system.wav" \
-  -F "self_name=Grant" -F 'timeline=[...]' -F "transcribe=true" \
-  -F 'known_voiceprints={"Grant":[...],"Caitlyn":[...]}'   # include your own
+  -F "self_name=Alice" -F 'timeline=[...]' -F "transcribe=true" \
+  -F 'known_voiceprints={"Alice":[...],"Bob":[...]}'   # include your own
 ```
 
 Response is the same shape with `"mode":"dual_channel"`; `speakers` includes a