Merge #200: lamp the subtitle upstreams

Closes #200

crates/arr-api/src/subtitles.rs

@@ -1714,6 +1714,10 @@ mod tests {
                 })
             })
         }
+
+        fn probe(&self) -> arr_subs::ProbeFuture<'_> {
+            Box::pin(async move { Ok(()) })
+        }
     }
 
     /// A provider that is configured but never answers.
@@ -1741,6 +1745,14 @@ mod tests {
                 })
             })
         }
+
+        fn probe(&self) -> arr_subs::ProbeFuture<'_> {
+            Box::pin(async move {
+                Err(arr_subs::Error::Unauthorized {
+                    provider: ProviderId::new("dead"),
+                })
+            })
+        }
     }
 
     /// Uppercases every cue. Enough to prove the pipeline, and it keeps cue
@@ -1769,6 +1781,10 @@ mod tests {
                     .collect())
             })
         }
+
+        fn probe(&self) -> arr_subs::translate::ProbeFuture<'_> {
+            Box::pin(async move { Ok(()) })
+        }
     }
 
     struct Fixture {