fix(neuron): install config at /etc/neuron/, not /etc/cortex/

The neuron package was shipping its config at /etc/cortex/neuron.toml,
which implied a shared config directory between two independent
packages. Move to /etc/neuron/neuron.toml — neuron owns its own etc
dir, consistent with its own /usr/lib/sysusers.d/neuron.conf and
/usr/lib/systemd/system/neuron.service. Updated the systemd unit's
ExecStart path and the example toml header to match.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

data/neuron.service

@@ -5,7 +5,7 @@ Wants=network-online.target
 
 [Service]
 Type=simple
-ExecStart=/usr/bin/neuron --config /etc/cortex/neuron.toml
+ExecStart=/usr/bin/neuron --config /etc/neuron/neuron.toml
 Restart=on-failure
 RestartSec=5
 User=cortex

neuron.example.toml

@@ -1,6 +1,6 @@
 # neuron.example.toml — example configuration
 #
-# Copy to /etc/cortex/neuron.toml and adjust for your environment.
+# Copy to /etc/neuron/neuron.toml and adjust for your environment.
 #
 # Environment variable overrides use NEURON_ prefix with __ separators:
 #   NEURON_PORT=9090

neuron.spec

@@ -52,8 +52,8 @@ cargo build --release -p neuron
 install -Dm755 target/release/neuron %{buildroot}%{_bindir}/neuron
 install -Dm644 data/neuron.service %{buildroot}%{_unitdir}/neuron.service
 install -Dm644 data/cortex-sysusers.conf %{buildroot}%{_sysusersdir}/neuron.conf
-install -dm750 %{buildroot}%{_sysconfdir}/cortex
-install -Dm640 neuron.example.toml %{buildroot}%{_sysconfdir}/cortex/neuron.toml
+install -dm750 %{buildroot}%{_sysconfdir}/neuron
+install -Dm640 neuron.example.toml %{buildroot}%{_sysconfdir}/neuron/neuron.toml
 
 %pre
 %sysusers_create_compat %{_builddir}/%{name}-%{version}/data/cortex-sysusers.conf
@@ -73,8 +73,8 @@ install -Dm640 neuron.example.toml %{buildroot}%{_sysconfdir}/cortex/neuron.toml
 %{_bindir}/neuron
 %{_unitdir}/neuron.service
 %{_sysusersdir}/neuron.conf
-%dir %attr(750,root,cortex) %{_sysconfdir}/cortex
-%config(noreplace) %attr(640,root,cortex) %{_sysconfdir}/cortex/neuron.toml
+%dir %attr(750,root,cortex) %{_sysconfdir}/neuron
+%config(noreplace) %attr(640,root,cortex) %{_sysconfdir}/neuron/neuron.toml
 
 %changelog
 * Tue Apr 15 2026 Rob Thijssen <grenade@rob.tn> - 0.1.0-1