feat(security): harden gateway boundaries and usage policies

Consolidate subscription usage policy enforcement, privacy-safe persistence, and gateway security hardening into one reviewable change.

Includes bounded HTTP and execution envelopes, header and protocol guards, DNS and relay validation, authentication and secret projection hardening, secure backup/install paths, and regression coverage.

crates/aether-runtime/state/src/redis/client.rs

@@ -17,12 +17,46 @@ pub(crate) const REDIS_COMMAND_LATENCY_BUCKETS_MS: [u64; 12] =
     [1, 5, 10, 25, 50, 100, 250, 500, 1_000, 2_500, 5_000, 10_000];
 const REDIS_COMMAND_LATENCY_BUCKET_COUNT: usize = REDIS_COMMAND_LATENCY_BUCKETS_MS.len() + 1;
 
-#[derive(Debug, Clone, serde::Serialize, serde::Deserialize, PartialEq, Eq)]
+#[derive(Clone, serde::Serialize, serde::Deserialize, PartialEq, Eq)]
 pub struct RedisClientConfig {
     pub url: String,
     pub key_prefix: Option<String>,
 }
 
+impl std::fmt::Debug for RedisClientConfig {
+    fn fmt(&self, formatter: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        formatter
+            .debug_struct("RedisClientConfig")
+            .field("url", &redact_redis_url_for_debug(&self.url))
+            .field("key_prefix_len", &self.key_prefix.as_ref().map(String::len))
+            .finish()
+    }
+}
+
+fn redact_redis_url_for_debug(raw: &str) -> String {
+    const MAX_DEBUG_URL_CHARS: usize = 512;
+    let raw = raw.trim();
+    let Ok(mut url) = url::Url::parse(raw) else {
+        return format!("[invalid-redis-url len={}]", raw.len());
+    };
+    let _ = url.set_username("");
+    let _ = url.set_password(None);
+    url.set_query(None);
+    url.set_fragment(None);
+    let rendered = url.to_string();
+    if rendered.chars().count() <= MAX_DEBUG_URL_CHARS {
+        rendered
+    } else {
+        format!(
+            "{}...",
+            rendered
+                .chars()
+                .take(MAX_DEBUG_URL_CHARS.saturating_sub(3))
+                .collect::<String>()
+        )
+    }
+}
+
 impl RedisClientConfig {
     pub fn validate(&self) -> Result<(), DataLayerError> {
         let raw = self.url.trim();
@@ -466,6 +500,25 @@ mod tests {
             .expect("lazy redis client should build");
     }
 
+    #[test]
+    fn redis_config_debug_redacts_url_credentials_and_query() {
+        let config = RedisClientConfig {
+            url: "redis://redis-user:[email protected]/0?token=redis-secret".into(),
+            key_prefix: Some("tenant-secret".into()),
+        };
+        let debug = format!("{config:?}");
+        for secret in [
+            "redis-user",
+            "redis-password",
+            "redis-secret",
+            "tenant-secret",
+        ] {
+            assert!(!debug.contains(secret), "debug leaked {secret}: {debug}");
+        }
+        assert!(debug.contains("redis.example"));
+        assert!(debug.contains("key_prefix_len"));
+    }
+
     #[test]
     fn blocking_stream_lane_count_uses_requested_as_floor() {
         let default_lanes = default_blocking_stream_lane_count();