fix(app): add catch block to SSE readSSE for stream read errors

Reports stream errors to onError callback instead of silently failing.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/app/src/adapters/claude-adapter.ts

@@ -103,6 +103,9 @@ async function readSSE(
         }
       }
     }
+  } catch (err) {
+    if (signal?.aborted) return
+    onError(err instanceof Error ? err.message : 'Stream read error')
   } finally {
     reader.cancel().catch(() => {})
   }

packages/app/src/adapters/openrouter-adapter.ts

@@ -109,6 +109,9 @@ async function readSSE(
         }
       }
     }
+  } catch (err) {
+    if (signal?.aborted) return
+    onError(err instanceof Error ? err.message : 'Stream read error')
   } finally {
     reader.cancel().catch(() => {})
   }

packages/app/src/composables/useAI.ts

@@ -311,6 +311,9 @@ async function readSSE(
         }
       }
     }
+  } catch (err) {
+    if (signal?.aborted) return
+    onError(err instanceof Error ? err.message : 'Stream read error')
   } finally {
     reader.cancel().catch(() => {})
   }