chore: rename mclogs filenames, asset paths, and runtime identifiers

Two file renames (docker/mclogs.ini -> docker/iblogs.ini,
web/public/css/mclogs.css -> web/public/css/iblogs.css) plus the
internal references that pointed at them (Dockerfile COPY directive,
the linux user name in the container).

Also catches the runtime identifier renames: env-var prefix MCLOGS_*
-> IBLOGS_* (compose files), browser cookie name MCLOGS_SETTINGS ->
IBLOGS_SETTINGS (web/public/js/log.js), production image tag
ghcr.io/aternosorg/mclogs:2 -> ghcr.io/indifferentketchup/iblogs:2,
and the README walk-through with the new branding.

example.config.json branding strings (legal contact, mclo.gs frontend
name) and visible UI text (taglines, meta descriptions) are deferred
to a separate branding commit.

Dockerfile

@@ -3,7 +3,7 @@ FROM dunglas/frankenphp:1-php8.5
 # System Setup
 RUN install-php-extensions mongodb zip
 
-ARG USER=mclogs
+ARG USER=iblogs
 RUN useradd ${USER} && \
     setcap CAP_NET_BIND_SERVICE=+eip /usr/local/bin/frankenphp
 
@@ -20,7 +20,7 @@ RUN --mount=type=cache,target=/tmp/cache/composer \
 
 # Application Setup
 COPY docker/Caddyfile /etc/frankenphp/Caddyfile
-COPY docker/mclogs.ini /usr/local/etc/php/conf.d/mclogs.ini
+COPY docker/iblogs.ini /usr/local/etc/php/conf.d/iblogs.ini
 
 COPY . .