Add low-signal short-turn screening

OpenJibo/docs/feature-backlog.md

@@ -975,6 +975,7 @@ For `1.0.19`:
   - next implementation pass should supply the real Azure Storage connection string / deployment wiring and validate the live round-trip in the storage account smoke test
 10. Update, backup, and restore proof - implemented (update creation and backup creation now survive persisted reloads; restore is the persisted-state rehydration proof path, not a new cloud API)
 11. STT upgrade and noise screening
+  - progress update (`2026-05-21`): added a low-signal short-turn screen in websocket finalization so filler-only fragments and stray single-token leftovers like `so command` get rejected before they can become bad turns, while preserving the existing yes/no and word-of-the-day short-turn flows
 12. Hosted capture/storage plan / indexing for group testing
 13. Binary-safe media storage / sync to cloud drive: OneDrive, Google Drive, Box, etc.
 14. Provider-backed news and weather parity polish

OpenJibo/docs/release-1.0.19-plan.md

@@ -84,6 +84,7 @@ The goal is to port these in small batches, capture the source-backed phrasing w
 - the restore proof is the persisted-state rehydration path; do not scope it into a new hosted restore API until we have real device evidence
 - continue alarm/gallery/yes-no cleanup from `1.0.18` evidence where regressions are still open
 - improve short-turn STT reliability and low-signal screening
+- the latest STT pass adds a websocket-side low-signal screen for filler-only and stray single-token leftovers while keeping yes/no and word-of-the-day turns intact
 
 ### 3. Pegasus-To-Cloud Platform Porting
 

OpenJibo/src/Jibo.Cloud/dotnet/src/Jibo.Cloud.Application/Services/WebSocketTurnFinalizationService.cs

@@ -106,6 +106,38 @@ public sealed class WebSocketTurnFinalizationService(
         "honestly"
     ];
 
+    private static readonly HashSet<string> SingleTokenUsableTranscripts = new(StringComparer.Ordinal)
+    {
+        "joke",
+        "funny",
+        "dance",
+        "boogie",
+        "time",
+        "date",
+        "today",
+        "day",
+        "hello",
+        "hi",
+        "hey",
+        "weather",
+        "news",
+        "radio",
+        "stop",
+        "sleep",
+        "sing",
+        "help",
+        "yes",
+        "yeah",
+        "yep",
+        "yup",
+        "sure",
+        "ok",
+        "okay",
+        "no",
+        "nope",
+        "nah"
+    };
+
     private static readonly HashSet<string> YesNoAffirmativeLeadTokens = new(StringComparer.Ordinal)
     {
         "yes",
@@ -1117,8 +1149,6 @@ public sealed class WebSocketTurnFinalizationService(
 
         if (ChitchatStateMachine.IsLikelyEmotionUtterance(transcript)) return true;
 
-        if (transcript.Length >= 6) return true;
-
         if (IsYesNoTurn(turn) && IsYesNoReplyTranscript(transcript)) return true;
 
         if (!string.IsNullOrWhiteSpace(pendingProactivityOffer) &&
@@ -1128,9 +1158,19 @@ public sealed class WebSocketTurnFinalizationService(
         if (listenRules.Any(rule =>
                 string.Equals(rule, "word-of-the-day/puzzle", StringComparison.OrdinalIgnoreCase))) return true;
 
+        if (IsLowSignalSingleTokenTranscript(transcript)) return false;
+
+        if (transcript.Length >= 6) return true;
+
         return transcript is "joke" or "dance" or "time" or "date" or "today" or "day" or "hello" or "hi" or "hey";
     }
 
+    private static bool IsLowSignalSingleTokenTranscript(string transcript)
+    {
+        var tokens = transcript.Split(' ', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
+        return tokens.Length == 1 && !SingleTokenUsableTranscripts.Contains(tokens[0]);
+    }
+
     private static bool IsYesNoTurn(TurnContext turn)
     {
         return ReadRules(turn, "listenRules")
@@ -1942,4 +1982,4 @@ public sealed class WebSocketTurnFinalizationService(
         Affirmative = 1,
         Negative = 2
     }
-}
+}

OpenJibo/tests/Jibo.Cloud.Tests/WebSockets/JiboWebSocketServiceTests.cs

@@ -3801,6 +3801,35 @@ public sealed class JiboWebSocketServiceTests
         Assert.Null(session.LastTranscript);
     }
 
+    [Fact]
+    public async Task ClientAsr_FillerPlusGenericCommand_IsIgnoredAsLowSignalNoise()
+    {
+        await _service.HandleMessageAsync(new WebSocketMessageEnvelope
+        {
+            HostName = "neo-hub.jibo.com",
+            Path = "/listen",
+            Kind = "neo-hub-listen",
+            Token = "hub-low-signal-command-token",
+            Text = """{"type":"LISTEN","transID":"trans-low-signal-command","data":{"rules":["wake-word"]}}"""
+        });
+
+        var replies = await _service.HandleMessageAsync(new WebSocketMessageEnvelope
+        {
+            HostName = "neo-hub.jibo.com",
+            Path = "/listen",
+            Kind = "neo-hub-listen",
+            Token = "hub-low-signal-command-token",
+            Text = """{"type":"CLIENT_ASR","transID":"trans-low-signal-command","data":{"text":"so command"}}"""
+        });
+
+        Assert.Empty(replies);
+
+        var session = _store.FindSessionByToken("hub-low-signal-command-token");
+        Assert.NotNull(session);
+        Assert.Null(session.LastIntent);
+        Assert.Null(session.LastTranscript);
+    }
+
     [Fact]
     public async Task BufferedAudio_WithSyntheticTranscriptHint_FinalizesThroughSttSeam()
     {
@@ -5212,4 +5241,4 @@ public sealed class JiboWebSocketServiceTests
             return items[^1];
         }
     }
-}
+}