feat: strip extra_body on the embedding and OCR paths with a warning

Stripping is load-bearing, not tidying: those transports never send the
value, so leaving it would make telemetry record a parameter never sent.

src/polygateway/embedding.py

@@ -41,7 +41,12 @@ from polygateway.middleware.ratelimit import QuotaGate
 from polygateway.middleware.retry import _failure_reason, backoff_delay
 from polygateway.middleware.telemetry import TelemetryEmitter
 from polygateway.sources import SourceCooldownMemo
-from polygateway.types import ChatRequest, EmbeddingResponse, LLMResponse
+from polygateway.types import (
+    ChatRequest,
+    EmbeddingResponse,
+    LLMResponse,
+    strip_unsupported_extra_body,
+)
 
 if TYPE_CHECKING:
     from collections.abc import Awaitable, Callable, Mapping
@@ -111,7 +116,9 @@ class EmbeddingClient:
         if expected_dim is not None and expected_dim < 1:
             raise ValueError("expected_dim 必须 ≥ 1")
         self._scope = scope
-        self._sources = list(sources)
+        # embed payload 硬编码 {model, input},带 extra_body 的源必须先剥离,
+        # 否则遥测会记录一个从未发出的采样参数(issue #4 决策 G)
+        self._sources = strip_unsupported_extra_body(list(sources), path="embedding")
         self._selector = selector
         self._quota = QuotaGate(limiter)
         self._breaker = BreakerGate(breaker)

src/polygateway/ocr.py

@@ -44,6 +44,7 @@ from polygateway.types import (
     OcrLayoutResult,
     OcrTextResult,
     Usage,
+    strip_unsupported_extra_body,
 )
 
 if TYPE_CHECKING:
@@ -113,7 +114,9 @@ class OcrClient:
         if quota_full not in ("wait", "fail_fast"):
             raise ValueError(f"quota_full 必须是 wait|fail_fast: {quota_full!r}")
         self._scope = scope
-        self._sources = list(sources)
+        # MonkeyOCR 只发 multipart 表单,带 extra_body 的源必须先剥离,否则
+        # 遥测会记录一个从未发出的采样参数(issue #4 决策 G)
+        self._sources = strip_unsupported_extra_body(list(sources), path="OCR")
         self._selector = selector
         self._feed_health = isinstance(selector, OutcomeAwareSelector)
         self._quota = QuotaGate(limiter)

src/polygateway/types.py

@@ -4,12 +4,15 @@
 fake,字段顺序即公共承诺;新增字段只增不删且必带默认值。
 """
 
+import dataclasses
 import json
 from collections.abc import Mapping
 from dataclasses import dataclass, field
 from types import MappingProxyType
 from typing import Any
 
+from loguru import logger
+
 _MISSING_DONE_DOMAIN = frozenset({"retry", "salvage"})
 
 _PROTECTED_OVERLAY_KEYS: Mapping[str, str] = MappingProxyType(
@@ -234,6 +237,34 @@ class SourceConfig:
         object.__setattr__(self, "extra_body", MappingProxyType(validated))
 
 
+def strip_unsupported_extra_body(
+    sources: list[SourceConfig], *, path: str
+) -> list[SourceConfig]:
+    """剥离非 chat 路径不消费的 `extra_body` 并 warning(issue #4 决策 G)。
+
+    剥离是必需的而非顺手清理: embedding 的 payload 硬编码 `{model, input}`、
+    MonkeyOCR 只发 multipart 表单,两者都不会把 `extra_body` 发出去;但遥测的
+    `sampling` 列会并上 `source.extra_body`,不剥离就等于**记录一个从未发出的
+    参数**——那是数据造假,污染的恰是事后复现的唯一依据。
+
+    选择 warning 放行而非报错: 这两条路径本无采样语义,配错的后果远轻于 chat
+    路径,不值得让下游整个装配起不来(2026-07-31 人类拍板)。
+    """
+    stripped = []
+    for source in sources:
+        if source.extra_body:
+            logger.warning(
+                "{} 路径暂不支持 extra_body,源 {} 的该配置已被忽略"
+                "(需要 dimensions 等参数请提 issue): {}",
+                path,
+                source.name,
+                dict(source.extra_body),
+            )
+            source = dataclasses.replace(source, extra_body={})
+        stripped.append(source)
+    return stripped
+
+
 @dataclass(frozen=True)
 class RetryPolicy:
     """重试策略;max_attempts = 总尝试次数(含首次,M1 设计 §2.3 统一语义)。"""