fix(bus): detect DashScope input length range as context overflow

crates/tinychannels-bus/src/context.rs

@@ -162,6 +162,13 @@ pub fn should_skip_memory_context_entry(key: &str, content: &str) -> bool {
 /// - **Token-count phrases** ("too many tokens", "token limit exceeded") collide
 ///   with per-minute token *rate* limits, which are transient. They count as
 ///   overflow only when no rate-limit marker is present.
+///
+/// This is a deliberate copy of `is_context_window_exceeded_message` in
+/// tinyinference's `crates/tinyinference-llm/src/failure.rs`, and its match
+/// list must track that function. It is duplicated rather than imported
+/// because this is the contract crate, which stays dependency-free and cannot
+/// take a dependency on the inference stack. When a provider phrasing is added
+/// there, add it here with the same test string.
 pub fn is_context_window_overflow_message(err: &str) -> bool {
     let lower = err.to_ascii_lowercase();
 
@@ -174,6 +181,9 @@ pub fn is_context_window_overflow_message(err: &str) -> bool {
         "prompt is too long",
         "input is too long",
         "greater than the context length",
+        // Alibaba / DashScope (Qwen): `"Range of input length should be
+        // [1, 98304]"` — the window is the range's upper bound.
+        "range of input length should be",
     ];
     if CONTEXT_HINTS.iter().any(|hint| lower.contains(hint)) {
         return true;

crates/tinychannels-bus/src/context_tests.rs

@@ -105,6 +105,21 @@ fn context_overflow_matches_lmstudio_n_keep_body() {
     ));
 }
 
+#[test]
+fn context_overflow_matches_dashscope_input_length_range() {
+    let body = "Provider returned error: {\"error\":{\"code\":\"invalid_parameter_error\",\
+                \"message\":\"Range of input length should be [1, 98304]\"}}";
+    assert!(is_context_window_overflow_message(body));
+}
+
+#[test]
+fn context_overflow_ignores_other_dashscope_parameter_errors() {
+    // Same DashScope error envelope, but not the input-length range.
+    let body = "Provider returned error: {\"error\":{\"code\":\"invalid_parameter_error\",\
+                \"message\":\"Range of temperature should be [0, 2)\"}}";
+    assert!(!is_context_window_overflow_message(body));
+}
+
 #[test]
 fn context_overflow_ignores_unrelated_and_rate_limit_bodies() {
     for body in [