telegram: fix parsing, add webpage reader, use gemini

- Fix Provider.hs to strip leading whitespace from OpenRouter responses
- Fix FunctionCall parser to handle missing 'arguments' field
- Use eitherDecode for better error messages on parse failures
- Switch to claude-sonnet-4.5 for main agent
- Use gemini-2.0-flash for conversation summarization (cheaper)
- Add read_webpage tool for fetching and summarizing URLs
- Add tagsoup to Haskell deps (unused, kept for future)

1 files changed, 9 insertions, 5 deletions

diff --git a/Omni/Agent/Provider.hs b/Omni/Agent/Provider.hs
index a8a5381..2ad6ea8 100644
--- a/Omni/Agent/Provider.hs
+++ b/Omni/Agent/Provider.hs
@@ -200,7 +200,7 @@ instance Aeson.FromJSON FunctionCall where
   parseJSON =
     Aeson.withObject "FunctionCall" <| \v ->
       (FunctionCall </ (v Aeson..: "name"))
-        <*> (v Aeson..: "arguments")
+        <*> (v Aeson..:? "arguments" Aeson..!= "{}")
 
 data Usage = Usage
   { usagePromptTokens :: Int,
@@ -322,14 +322,18 @@ chatOpenAI cfg tools messages = do
 
   response <- HTTP.httpLBS req
   let status = HTTP.getResponseStatusCode response
+      respBody = HTTP.getResponseBody response
+      cleanedBody = BL.dropWhile (\b -> b `elem` [0x0a, 0x0d, 0x20]) respBody
   if status >= 200 && status < 300
-    then case Aeson.decode (HTTP.getResponseBody response) of
-      Just resp ->
+    then case Aeson.eitherDecode cleanedBody of
+      Right resp ->
         case respChoices resp of
           (c : _) -> pure (Right (ChatResult (choiceMessage c) (respUsage resp)))
           [] -> pure (Left "No choices in response")
-      Nothing -> pure (Left "Failed to parse response")
-    else pure (Left ("HTTP error: " <> tshow status <> " - " <> TE.decodeUtf8 (BL.toStrict (HTTP.getResponseBody response))))
+      Left err -> do
+        let bodyPreview = TE.decodeUtf8 (BL.toStrict (BL.take 500 cleanedBody))
+        pure (Left ("Failed to parse response: " <> Text.pack err <> " | Body: " <> bodyPreview))
+    else pure (Left ("HTTP error: " <> tshow status <> " - " <> TE.decodeUtf8 (BL.toStrict respBody)))
 
 chatOllama :: ProviderConfig -> [ToolApi] -> [Message] -> IO (Either Text ChatResult)
 chatOllama cfg tools messages = do