chore: move default ports out of common-collision ranges

Previous defaults collided with well-trodden infra services and with
the Linux ephemeral port range:

- cortex API     8000 — common dev-server default (Django, minio UI)
- cortex metrics 9100 — Prometheus node_exporter default
- neuron API     9090 — Cockpit default on Fedora, Prometheus self

Move to helexa-themed palindromic ports, all below Linux's
32768-60999 ephemeral range and not registered to any well-known
service:

- cortex API     31313
- cortex metrics 31314
- neuron API     13131

Updated places:
- cortex.example.toml, neuron.example.toml defaults
- default impls in cortex-core and neuron config
- cortex-cli --endpoint default for the status subcommand
- doc comments citing example URLs
- README.md and CLAUDE.md snippets

Consumers already on the old ports need a one-line edit in their
/etc/cortex/cortex.toml or /etc/neuron/neuron.toml to match;
firewall rules and prometheus scrape configs will also need
updating.

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

crates/cortex-core/src/config.rs

@@ -22,9 +22,9 @@ fn default_models_path() -> String {
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct GatewaySettings {
-    /// Address to listen on for API requests (e.g. "0.0.0.0:8000")
+    /// Address to listen on for API requests (e.g. "0.0.0.0:31313")
     pub listen: String,
-    /// Address to listen on for Prometheus metrics (e.g. "0.0.0.0:9100")
+    /// Address to listen on for Prometheus metrics (e.g. "0.0.0.0:31314")
     pub metrics_listen: String,
 }
 
@@ -50,7 +50,7 @@ pub enum EvictionStrategy {
 pub struct NeuronEndpoint {
     /// Human-readable node name (e.g. "beast")
     pub name: String,
-    /// Base URL of the neuron daemon (e.g. "http://beast.internal:9090")
+    /// Base URL of the neuron daemon (e.g. "http://beast.internal:13131")
     pub endpoint: String,
 }
 
@@ -70,8 +70,8 @@ impl Default for GatewayConfig {
     fn default() -> Self {
         Self {
             gateway: GatewaySettings {
-                listen: "0.0.0.0:8000".into(),
-                metrics_listen: "0.0.0.0:9100".into(),
+                listen: "0.0.0.0:31313".into(),
+                metrics_listen: "0.0.0.0:31314".into(),
             },
             eviction: EvictionSettings {
                 strategy: EvictionStrategy::Lru,

crates/cortex-core/src/node.rs

@@ -6,7 +6,7 @@ use std::collections::HashMap;
 #[derive(Debug, Clone)]
 pub struct NodeState {
     pub name: String,
-    /// Base URL of the neuron daemon (e.g. "http://beast.internal:9090").
+    /// Base URL of the neuron daemon (e.g. "http://beast.internal:13131").
     pub endpoint: String,
     pub healthy: bool,
     pub models: HashMap<String, ModelEntry>,