fix(ai): retry and diagnose transient provider failures

crates/dbx-core/src/agent_loop.rs

@@ -608,6 +608,19 @@ pub async fn run_agent_loop(
             final_text.push_str(&message);
         }
         LoopExit::Interrupted(error) => {
+            // The retry layer records the HTTP-level cause; this records the
+            // agent-level exit so a failure still leaves a trace even after the
+            // user dismisses the on-screen message. Cancellation has its own arm
+            // above and never reaches here. The error is re-scrubbed here so a
+            // credential cannot reach the log file even if a provider echo slipped
+            // past the source-side redaction.
+            let error = ai::redact_secrets(&error, &ai::sensitive_values(config));
+            log::warn!(
+                "[agent] stream interrupted; provider={:?} model={} agent_mode={} error={error}",
+                config.provider,
+                config.model,
+                is_agent_mode
+            );
             let message = if final_text.trim().is_empty() {
                 format!("Agent stream stopped before completion: {error}.")
             } else {