v1.0.4

v1.0.4 — fix enhance/deepfilter + JSON logging overhaul

Bug fix: /v1/audio/enhance/deepfilter no longer 400s before first
load. The predicate was checking a private attribute that only
exists post-lazy-load.

Logging: single centralised init path through audiolla.logging,
line-delimited JSON, LOG_LEVEL env var, file:line:func + service /
version / pid / host on every record, X-Request-Id correlation
honoured both ways (inbound + outbound), per-request summary log
level-scaled to status code (DEBUG /healthz, INFO 2xx/3xx, WARN 4xx,
ERROR 5xx) with method / path / status / duration_ms / client_ip /
user_agent / request+response byte sizes.