fix(komide): bound feed/episode fetch, fix backoff overflow, add coverage

crates/horismos/src/lib.rs

@@ -89,6 +89,15 @@ mod tests {
         assert_eq!(config.kritike.scan_interval_hours, 24);
     }
 
+    #[test]
+    fn default_komide_config_has_correct_values() {
+        let config = Config::default();
+        assert_eq!(config.komide.max_feed_bytes, 20 * 1024 * 1024);
+        assert_eq!(config.komide.max_episode_bytes, 1024 * 1024 * 1024);
+        assert_eq!(config.komide.max_backoff_minutes, 240);
+        assert_eq!(config.komide.fetch_timeout_secs, 30);
+    }
+
     #[test]
     fn default_syndesmos_config_has_correct_values() {
         let config = Config::default();

crates/horismos/src/subsystems.rs

@@ -403,6 +403,10 @@ pub struct KomideConfig {
     pub auto_download_latest_n: u64,
     /// Request timeout for feed fetches in seconds.
     pub fetch_timeout_secs: u64,
+    /// Maximum feed response body size in bytes; larger responses are rejected.
+    pub max_feed_bytes: u64,
+    /// Maximum episode download size in bytes; larger downloads are rejected.
+    pub max_episode_bytes: u64,
     /// Maximum exponential-backoff window (minutes) between feed polls after
     /// consecutive failures.
     pub max_backoff_minutes: u64,
@@ -421,6 +425,8 @@ impl Default for KomideConfig {
             news_retention_articles: 500,
             auto_download_latest_n: 3,
             fetch_timeout_secs: 30,
+            max_feed_bytes: 20 * 1024 * 1024,
+            max_episode_bytes: 1024 * 1024 * 1024,
             max_backoff_minutes: 240,
             jitter_percent: 10.0,
         }

crates/komide/Cargo.toml

@@ -22,6 +22,7 @@ jiff            = { workspace = true }
 rstest          = { workspace = true }
 tokio           = { workspace = true, features = ["full"] }
 sqlx            = { workspace = true }
+tempfile        = "3"
 
 [package.metadata.kanon]
 maturity = "alpha"

crates/komide/src/error.rs

@@ -36,6 +36,14 @@ pub enum KomideError {
         location: snafu::Location,
     },
 
+    #[snafu(display("response body for {url} exceeds the {limit}-byte cap"))]
+    ResponseTooLarge {
+        url: String,
+        limit: u64,
+        #[snafu(implicit)]
+        location: snafu::Location,
+    },
+
     #[snafu(display("invalid feed URL: {url}"))]
     InvalidUrl {
         url: String,