feat: Add ErrorFrame emission to TTS/STT services for pipeline error detection (#2881)

* feat: Add ErrorFrame emission to TTS/STT services for pipeline error detection

- Add ErrorFrame emission to all major TTS/STT services during initialization and runtime failures
- Services updated: Cartesia, ElevenLabs, Deepgram, AssemblyAI, Rime, Azure
- ErrorFrame objects emitted with fatal=False for graceful degradation
- Enables on_pipeline_error event handler to detect service failures programmatically
- Add comprehensive pytest test suite to verify ErrorFrame emission
- Fixes issue where services failed gracefully but didn't emit ErrorFrame objects

This allows developers to implement real-time error monitoring and alerting
using the on_pipeline_error event handler introduced in v0.0.90.

* Update STT and TTS services to use consistent error handling pattern

- Improves error handling consistency across all services

* Add changelog entry for STT/TTS error handling improvements

* Linting issues Resolved

* Azure STT ErrorFrames added with consistent patterns

* Cartesia STT and Deepgram STT; additional fixes made

* Removed Fatal Flags across services, removed duplication

* Moving the changelog entry to the correct place.

* Refactoring some classes to use yield instead of push_error directly.

* Fixing ruff format.

---------

Co-authored-by: Filipi Fuchter <filipi87@gmail.com>

src/pipecat/services/groq/tts.py

@@ -13,7 +13,13 @@ from typing import AsyncGenerator, Optional
 from loguru import logger
 from pydantic import BaseModel
 
-from pipecat.frames.frames import Frame, TTSAudioRawFrame, TTSStartedFrame, TTSStoppedFrame
+from pipecat.frames.frames import (
+    ErrorFrame,
+    Frame,
+    TTSAudioRawFrame,
+    TTSStartedFrame,
+    TTSStoppedFrame,
+)
 from pipecat.services.tts_service import TTSService
 from pipecat.transcriptions.language import Language
 from pipecat.utils.tracing.service_decorators import traced_tts
@@ -150,5 +156,6 @@ class GroqTTSService(TTSService):
                     yield TTSAudioRawFrame(bytes, frame_rate, channels)
         except Exception as e:
             logger.error(f"{self} exception: {e}")
+            yield ErrorFrame(error=f"{self} error: {e}")
 
         yield TTSStoppedFrame()