Refactor project structure and enhance backend integration

- Expanded package inclusion in `pyproject.toml` to support new modules.
- Introduced new `adapters` and `protocol` packages for better organization.
- Added backend adapter implementations for control plane integration.
- Updated main application imports to reflect new package structure.
- Removed deprecated core components and adjusted documentation accordingly.
- Enhanced architecture documentation to clarify the new runtime and integration layers.

engine/runtime/pipeline/__init__.py

@@ -0,0 +1 @@
+"""Runtime pipeline package."""

engine/runtime/pipeline/asr_flow.py

@@ -0,0 +1,13 @@
+"""ASR flow helpers extracted from the duplex pipeline.
+
+This module is intentionally lightweight for phase-wise migration.
+"""
+
+from __future__ import annotations
+
+from providers.common.base import ASRResult
+
+
+def is_final_result(result: ASRResult) -> bool:
+    """Return whether an ASR result is final."""
+    return bool(result.is_final)

engine/runtime/pipeline/constants.py

@@ -0,0 +1,6 @@
+"""Shared constants for the runtime duplex pipeline."""
+
+TRACK_AUDIO_IN = "audio_in"
+TRACK_AUDIO_OUT = "audio_out"
+TRACK_CONTROL = "control"
+PCM_FRAME_BYTES = 640  # 16k mono pcm_s16le, 20ms

engine/runtime/pipeline/events_out.py

@@ -0,0 +1,12 @@
+"""Output-event shaping helpers for the runtime pipeline."""
+
+from __future__ import annotations
+
+from typing import Any, Dict
+
+
+def assistant_text_delta_event(text: str, **extra: Any) -> Dict[str, Any]:
+    """Build a normalized assistant text delta payload."""
+    payload: Dict[str, Any] = {"type": "assistant.text.delta", "text": str(text)}
+    payload.update(extra)
+    return payload

engine/runtime/pipeline/interrupts.py

@@ -0,0 +1,8 @@
+"""Interruption-related helpers extracted from the duplex pipeline."""
+
+from __future__ import annotations
+
+
+def should_interrupt(min_duration_ms: int, detected_ms: int) -> bool:
+    """Decide whether interruption conditions are met."""
+    return int(detected_ms) >= max(0, int(min_duration_ms))

engine/runtime/pipeline/llm_flow.py

@@ -0,0 +1,13 @@
+"""LLM flow helpers extracted from the duplex pipeline.
+
+This module is intentionally lightweight for phase-wise migration.
+"""
+
+from __future__ import annotations
+
+from providers.common.base import LLMStreamEvent
+
+
+def is_done_event(event: LLMStreamEvent) -> bool:
+    """Return whether an LLM stream event signals completion."""
+    return str(event.type) == "done"

engine/runtime/pipeline/tooling.py

@@ -0,0 +1,13 @@
+"""Tooling helpers extracted from the duplex pipeline."""
+
+from __future__ import annotations
+
+from typing import Any
+
+
+def normalize_tool_name(name: Any, aliases: dict[str, str]) -> str:
+    """Normalize tool name with alias mapping."""
+    normalized = str(name or "").strip()
+    if not normalized:
+        return ""
+    return aliases.get(normalized, normalized)

engine/runtime/pipeline/tts_flow.py

@@ -0,0 +1,15 @@
+"""TTS flow helpers extracted from the duplex pipeline.
+
+This module is intentionally lightweight for phase-wise migration.
+"""
+
+from __future__ import annotations
+
+from providers.common.base import TTSChunk
+
+
+def chunk_duration_ms(chunk: TTSChunk) -> float:
+    """Estimate chunk duration in milliseconds for pcm16 mono."""
+    if chunk.sample_rate <= 0:
+        return 0.0
+    return (len(chunk.audio) / 2.0 / float(chunk.sample_rate)) * 1000.0