diff --git a/core/model-framework/__init__.py b/core/model-framework/__init__.py
new file mode 100644
index 0000000..d70d6b2
--- /dev/null
+++ b/core/model-framework/__init__.py
@@ -0,0 +1,48 @@
+# -*- coding: utf-8 -*-
+"""iAOP-Core · 模型框架层（AI Model Framework）。
+
+对应 PRD 5.3「③ AI 模型框架」与 EPIC #5（内核平台化改造）。
+
+当前已交付（自包含，不依赖未合并分支）：
+- ``quality_forecast``：质量预测模型模板化（固定主干 + 配方加载），
+  issue #36。同一主干代码不变，切换行业/工况只改配方（声明式 JSON
+  超参包）——对齐 PRD 5.3「固定主干 + 可配置超参」默认模式。
+
+规划（待相关 PR 合入后无缝对接，业务侧零改动）：
+- ``model_recipe``：Model Recipe 插件接口（issue #34，PR #102 待审核）。
+  ``quality_forecast`` 的主干届时可注册为 ``register_backbone`` 的一个
+  具名主干，配方可映射为一条 ``ModelRecipe``。
+"""
+from model_framework.quality_forecast import (
+    Accuracy,
+    BACKBONES,
+    ModelHandle,
+    QualityForecastError,
+    QualityForecastModel,
+    Recipe,
+    build_from_recipe,
+    dnn_backbone,
+    gbdt_backbone,
+    list_sample_recipes,
+    load_recipe,
+    register_backbone,
+    sample_recipe_path,
+    stub_backbone,
+)
+
+__all__ = [
+    "Recipe",
+    "Accuracy",
+    "QualityForecastError",
+    "QualityForecastModel",
+    "ModelHandle",
+    "BACKBONES",
+    "register_backbone",
+    "gbdt_backbone",
+    "dnn_backbone",
+    "stub_backbone",
+    "load_recipe",
+    "build_from_recipe",
+    "list_sample_recipes",
+    "sample_recipe_path",
+]
diff --git a/core/model-framework/_sanity_check.py b/core/model-framework/_sanity_check.py
new file mode 100644
index 0000000..d8483c0
--- /dev/null
+++ b/core/model-framework/_sanity_check.py
@@ -0,0 +1,71 @@
+# -*- coding: utf-8 -*-
+"""质量预测模型模板化 sanity 检查（无构建环境下的离线基本验证）。
+
+验证 PRD 5.3 验收口径「同框架加载 Ti / 树脂两套配方均跑通」：
+1. 两套样例配方均可被 ``build_from_recipe`` 加载；
+2. 加载后模型可 fit / predict / evaluate 走通完整链路；
+3. 切换模板仅改配方，模型代码（``type(m1) == type(m2)``）零改动；
+4. 两套配方的 backbone / 特征列确实不同（确属两套模板，非同一份复制）。
+
+用法：python _sanity_check.py
+"""
+import os
+import sys
+
+HERE = os.path.dirname(os.path.abspath(__file__))
+if HERE not in sys.path:
+    sys.path.insert(0, HERE)
+
+from quality_forecast import (  # noqa: E402
+    build_from_recipe,
+    list_sample_recipes,
+    sample_recipe_path,
+)
+
+
+def main() -> int:
+    failures = []
+
+    names = list_sample_recipes()
+    required = ("recipe.ti.json", "recipe.resin.json")
+    for r in required:
+        if r not in names:
+            failures.append(f"缺少样例配方：{r}")
+
+    models = {}
+    for r in required:
+        try:
+            m = build_from_recipe(sample_recipe_path(r))
+            # 用配方声明的特征数构造演示数据
+            n_feat = len(m.recipe_meta["feature_columns"]) or 2
+            X = [[float(i + j) for j in range(n_feat)] for i in range(10)]
+            y = [float(i % 4) + 1.0 for i in range(10)]
+            m.fit(X, y)
+            preds = m.predict(X)
+            assert len(preds) == len(y), "预测长度异常"
+            m.evaluate(X, y)
+            models[r] = m
+        except Exception as exc:  # pragma: no cover - 诊断输出
+            failures.append(f"{r} 加载/训练/评估失败：{exc!r}")
+
+    # 切换模板仅改配方，模型代码零改动
+    if len(models) == 2:
+        ms = list(models.values())
+        if type(ms[0]) is not type(ms[1]):
+            failures.append("两套配方使用了不同的模型类，违反「模型代码零改动」")
+        if (models["recipe.ti.json"].recipe_meta["feature_columns"]
+                == models["recipe.resin.json"].recipe_meta["feature_columns"]):
+            failures.append("Ti/树脂配方特征列完全相同，疑似复制")
+
+    if failures:
+        print("FAIL")
+        for f in failures:
+            print(" -", f)
+        return 1
+    print(f"OK: {len(required)} 套配方均加载/训练/评估通过，"
+          f"模型代码零改动（type 一致），PRD 5.3 验收口径达成")
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())
diff --git a/core/model-framework/quality_forecast.py b/core/model-framework/quality_forecast.py
new file mode 100644
index 0000000..325df28
--- /dev/null
+++ b/core/model-framework/quality_forecast.py
@@ -0,0 +1,534 @@
+# -*- coding: utf-8 -*-
+"""质量预测模型模板化（固定主干 + 配方加载）。
+
+对应 issue #36（父 EPIC #5「③ AI 模型框架 配置化重构」、PRD 5.3
+「网络结构策略 / 模板化技术路径」）。
+
+PRD 5.3 的核心诉求
+------------------
+
+质量预测属于 PRD 5.3「四类模型模板」之一（① 质量预测），采用
+「**固定主干网络 + 可配置超参**」为默认模式：同一主干代码不变，
+切换行业/工况只改 *配方（recipe）* —— 一个声明式 JSON 超参包。
+
+本模块交付什么
+--------------
+
+1. **``QualityForecastModel``**：固定主干的质量预测模型。默认主干是
+   ``gbdt``（梯度提升回归，PRD 5.3 推荐的监督回归默认结构）；当运行
+   环境存在 ``sklearn`` 时自动升级为真实实现，否则退化为确定性 stub，
+   保证边缘 / 离线 / CI 环境可加载与校验——与 issue #34 / #35 的
+   「numpy/sklearn 可选」策略一致。
+2. **``Recipe`` 配方加载器**：声明式 JSON 超参包（``load_recipe`` /
+   ``build_from_recipe``）。配方描述「主干类型 + 超参 + 特征列 + 目标列
+   + 验收口径」，业务侧只 ``build_from_recipe(path)`` 一行即可拿到一个
+   可训练/可推理的模型——切换模板仅改配方，模型代码零改动。
+3. **``Accuracy`` 验收口径**：PRD 5.3 / 第 6 章里程碑要求「关键质量指标
+   预测准确率 ≥ 90%」。``evaluate`` 直接给出准确率 / MAE / RMSE，便于
+   配置台与 UAT 直接读取。
+4. **样例配方（``samples/`` JSON）**：Ti（海绵钛氯化车间）+ 树脂两套
+   质量预测超参包样例，验证「同框架加载两套配方均跑通」的验收口径。
+
+与 issue #34 ``model_recipe`` 的关系
+------------------------------------
+
+接口风格对齐 #34 的 ``ModelHandle`` / ``ModelRecipe``（``fit`` / ``predict``
+/ ``to_dict``、不可变声明式数据对象）。本模块**自包含、不依赖 #34 未合并
+的 ``model_recipe``**，待 #34（PR #102）合入后，质量预测主干可平滑注册为
+``register_backbone("gbdt", ...)`` 的一个具名主干，配方可映射为一条
+``ModelRecipe``——届时本模块零业务侧改动。
+
+零外部强依赖
+------------
+
+* 主干默认走纯 Python stub（``StubBackbone``）：无 sklearn 时也能加载、
+  构造、（伪）拟合与预测，保证 CI 可加载与校验；
+* 存在 ``sklearn`` 时，``gbdt`` 主干自动升级为真实
+  ``GradientBoostingRegressor`` 实现，其余情况退化为 stub，不影响接口
+  契约与测试。
+"""
+
+from __future__ import annotations
+
+import json
+import math
+import os
+from dataclasses import dataclass, field
+from typing import Any, Dict, List, Optional, Sequence, Tuple
+
+__all__ = [
+    # 数据对象
+    "Recipe",
+    "Accuracy",
+    "QualityForecastError",
+    # 模型
+    "QualityForecastModel",
+    "ModelHandle",
+    # 主干工厂
+    "BACKBONES",
+    "register_backbone",
+    "gbdt_backbone",
+    "dnn_backbone",
+    "stub_backbone",
+    # 配方 API
+    "load_recipe",
+    "build_from_recipe",
+    "list_sample_recipes",
+    "sample_recipe_path",
+]
+
+
+class QualityForecastError(Exception):
+    """质量预测模板化层的统一异常（配方非法 / 主干未注册 / 校验失败）。"""
+
+
+# ---------------------------------------------------------------------------
+# 配方（Recipe）：声明式超参包，不可变数据对象
+# ---------------------------------------------------------------------------
+
+#: PRD 5.3 允许的固定主干类型（默认 gbdt，PRD 5.3 推荐监督回归默认结构）
+ALLOWED_BACKBONES = ("gbdt", "dnn", "stub")
+
+#: PRD 5.3 / 第 6 章里程碑：质量预测准确率验收线 ≥ 90%
+DEFAULT_ACCURACY_FLOOR = 0.90
+
+
+@dataclass(frozen=True)
+class Recipe:
+    """质量预测配方（声明式超参包）。
+
+    一个 Recipe 描述「用什么固定主干 + 如何从超参构造一个可训练/可推理的
+    质量预测模型 + 用哪些特征/目标列 + 验收口径」。它是不可变数据对象，
+    ``to_dict`` / ``from_dict`` 可序列化往返，便于配置台展示与审计。
+
+    切换行业/工况只改 Recipe，模型代码（``QualityForecastModel``）零改动
+    ——对齐 PRD 5.3「固定主干 + 可配置超参」默认模式。
+    """
+
+    name: str
+    backbone: str = "gbdt"
+    hyperparams: Dict[str, Any] = field(default_factory=dict)
+    feature_columns: Tuple[str, ...] = field(default_factory=tuple)
+    target_column: str = "quality_index"
+    accuracy_floor: float = DEFAULT_ACCURACY_FLOOR
+    industry: str = ""
+    notes: str = ""
+
+    def __post_init__(self) -> None:
+        if not self.name:
+            raise QualityForecastError("Recipe 缺少 name")
+        if self.backbone not in ALLOWED_BACKBONES:
+            raise QualityForecastError(
+                f"非法主干类型 {self.backbone!r}，允许：{ALLOWED_BACKBONES}")
+        if self.accuracy_floor < 0 or self.accuracy_floor > 1:
+            raise QualityForecastError(
+                f"accuracy_floor 越界：{self.accuracy_floor}（应在 [0,1]）")
+
+    def to_dict(self) -> Dict[str, Any]:
+        return {
+            "name": self.name,
+            "backbone": self.backbone,
+            "hyperparams": dict(self.hyperparams),
+            "feature_columns": list(self.feature_columns),
+            "target_column": self.target_column,
+            "accuracy_floor": self.accuracy_floor,
+            "industry": self.industry,
+            "notes": self.notes,
+        }
+
+    @classmethod
+    def from_dict(cls, data: Dict[str, Any]) -> "Recipe":
+        try:
+            return cls(
+                name=data["name"],
+                backbone=data.get("backbone", "gbdt"),
+                hyperparams=dict(data.get("hyperparams", {})),
+                feature_columns=tuple(data.get("feature_columns", [])),
+                target_column=data.get("target_column", "quality_index"),
+                accuracy_floor=float(data.get(
+                    "accuracy_floor", DEFAULT_ACCURACY_FLOOR)),
+                industry=data.get("industry", ""),
+                notes=data.get("notes", ""),
+            )
+        except KeyError as exc:  # pragma: no cover - 防御性
+            raise QualityForecastError(f"配方缺少必填字段：{exc}") from exc
+
+
+def load_recipe(path: str) -> Recipe:
+    """从 JSON 文件加载一个质量预测配方。
+
+    配方 JSON 结构见 ``Recipe.to_dict``；样例见 ``samples/``。
+    """
+    with open(path, "r", encoding="utf-8") as fh:
+        data = json.load(fh)
+    if not isinstance(data, dict):
+        raise QualityForecastError(f"配方根必须是对象：{path}")
+    return Recipe.from_dict(data)
+
+
+# ---------------------------------------------------------------------------
+# 主干工厂：固定主干网络（gbdt / dnn / stub）
+# ---------------------------------------------------------------------------
+
+class ModelHandle:
+    """统一模型句柄：fit / predict / to_dict，与硬件和具体库无关。
+
+    业务代码只持有 ``ModelHandle``，不感知底层是 sklearn 还是 stub。
+    """
+
+    def __init__(self, backbone: str, params: Dict[str, Any],
+                 fitted: bool = False, meta: Optional[Dict[str, Any]] = None):
+        self.backbone = backbone
+        self.params = dict(params)
+        self._fitted = fitted
+        self.meta: Dict[str, Any] = dict(meta or {})
+
+    @property
+    def fitted(self) -> bool:
+        return self._fitted
+
+    def fit(self, X: Sequence[Sequence[float]], y: Sequence[float]) -> "ModelHandle":
+        """拟合主干。stub 主干记录均值/极差用于确定性预测。"""
+        X = list(X)
+        y = list(y)
+        if not X or not y:
+            raise QualityForecastError("训练数据为空")
+        if len(X) != len(y):
+            raise QualityForecastError(
+                f"X/y 样本数不一致：{len(X)} != {len(y)}")
+        self._fit_impl(X, y)
+        self._fitted = True
+        return self
+
+    # 子类/工厂填充
+    def _fit_impl(self, X: Sequence[Sequence[float]], y: Sequence[float]) -> None:
+        raise NotImplementedError
+
+    def predict(self, X: Sequence[Sequence[float]]) -> List[float]:
+        if not self._fitted:
+            raise QualityForecastError("模型未拟合，无法预测")
+        return [self._predict_one(list(row)) for row in X]
+
+    def _predict_one(self, row: Sequence[float]) -> float:
+        raise NotImplementedError
+
+    def to_dict(self) -> Dict[str, Any]:
+        return {
+            "backbone": self.backbone,
+            "params": dict(self.params),
+            "fitted": self._fitted,
+            "meta": dict(self.meta),
+        }
+
+
+class _StubBackbone(ModelHandle):
+    """确定性 stub 主干：无 sklearn 时的保底实现。
+
+    拟合阶段记录训练目标的均值与极差；预测返回一个由输入求和驱动的
+    确定性值（落在训练目标范围内），保证可复现、可校验、可对比，便于
+    CI 与配置台预览。
+    """
+
+    def __init__(self, params: Dict[str, Any]):
+        super().__init__(backbone="stub", params=params)
+        self._y_mean: float = 0.0
+        self._y_amp: float = 1.0
+
+    def _fit_impl(self, X, y) -> None:
+        self._y_mean = sum(y) / len(y)
+        self._y_amp = (max(y) - min(y)) or 1.0
+        self.meta.update({"y_mean": self._y_mean, "y_amp": self._y_amp})
+
+    def _predict_one(self, row) -> float:
+        # 确定性：输入和的 tanh 压缩到 [y_mean-amp/2, y_mean+amp/2]
+        s = sum(float(v) for v in row) if row else 0.0
+        # 归一化到 [-1,1] 附近，再映射回目标域
+        norm = math.tanh(s / (self._y_amp or 1.0))
+        return self._y_mean + 0.5 * self._y_amp * norm
+
+
+class _SklearnGbdtBackbone(ModelHandle):
+    """真实 GBDT 主干（sklearn GradientBoostingRegressor）。
+
+    仅当运行环境存在 sklearn 时启用；与 stub 接口完全一致。
+    """
+
+    def __init__(self, params: Dict[str, Any]):
+        super().__init__(backbone="gbdt", params=params)
+        # 延迟 import，避免无 sklearn 环境加载失败
+        from sklearn.ensemble import GradientBoostingRegressor  # type: ignore
+        self._Clz = GradientBoostingRegressor
+        self._model: Any = None
+
+    def _fit_impl(self, X, y) -> None:
+        kw = {
+            "n_estimators": int(self.params.get("n_estimators", 100)),
+            "max_depth": int(self.params.get("max_depth", 3)),
+            "learning_rate": float(self.params.get("learning_rate", 0.1)),
+            "random_state": int(self.params.get("random_state", 42)),
+        }
+        self._model = self._Clz(**kw)
+        self._model.fit(list(X), list(y))
+        self.meta.update(kw)
+
+    def _predict_one(self, row) -> float:
+        return float(self._model.predict([list(row)])[0])
+
+
+class _SklearnDnnBackbone(ModelHandle):
+    """真实轻量 DNN 主干（sklearn MLPRegressor）。
+
+    PRD 5.3 备选结构；仅当运行环境存在 sklearn 时启用。
+    """
+
+    def __init__(self, params: Dict[str, Any]):
+        super().__init__(backbone="dnn", params=params)
+        from sklearn.neural_network import MLPRegressor  # type: ignore
+        self._Clz = MLPRegressor
+        self._model: Any = None
+
+    def _fit_impl(self, X, y) -> None:
+        kw = {
+            "hidden_layer_sizes": tuple(
+                self.params.get("hidden_layer_sizes", (32, 16))),
+            "max_iter": int(self.params.get("max_iter", 500)),
+            "random_state": int(self.params.get("random_state", 42)),
+        }
+        self._model = self._Clz(**kw)
+        self._model.fit(list(X), list(y))
+        self.meta.update({"hidden_layer_sizes": list(kw["hidden_layer_sizes"]),
+                          "max_iter": kw["max_iter"]})
+
+    def _predict_one(self, row) -> float:
+        return float(self._model.predict([list(row)])[0])
+
+
+def _has_sklearn() -> bool:
+    try:
+        import sklearn  # noqa: F401
+        return True
+    except Exception:
+        return False
+
+
+def stub_backbone(hyperparams: Dict[str, Any]) -> ModelHandle:
+    """stub 主干工厂（恒可用）。"""
+    return _StubBackbone(hyperparams)
+
+
+def gbdt_backbone(hyperparams: Dict[str, Any]) -> ModelHandle:
+    """gbdt 主干工厂：有 sklearn 用真实 GBDT，否则退化为 stub。
+
+    PRD 5.3 推荐的监督回归默认结构（梯度提升回归）。
+    """
+    if _has_sklearn():
+        return _SklearnGbdtBackbone(hyperparams)
+    # 无 sklearn：退化 stub 但保留声明主干名，便于审计
+    h = _StubBackbone(hyperparams)
+    h.meta["degraded_from"] = "gbdt"
+    return h
+
+
+def dnn_backbone(hyperparams: Dict[str, Any]) -> ModelHandle:
+    """dnn 主干工厂：有 sklearn 用真实 MLP，否则退化为 stub。"""
+    if _has_sklearn():
+        return _SklearnDnnBackbone(hyperparams)
+    h = _StubBackbone(hyperparams)
+    h.meta["degraded_from"] = "dnn"
+    return h
+
+
+#: 主干注册表：新增结构走 ``register_backbone`` 注册，不动内核
+#: （对齐 PRD 5.3「新增结构走插件注册」理念，风格对齐 #34）。
+BACKBONES: Dict[str, Any] = {
+    "gbdt": gbdt_backbone,
+    "dnn": dnn_backbone,
+    "stub": stub_backbone,
+}
+
+
+def register_backbone(name: str, factory: Any) -> None:
+    """注册一个新主干工厂 ``factory(hyperparams) -> ModelHandle``。
+
+    允许高级行业模板声明非默认主干（如自研网络），不动内核——对齐 PRD
+    「新增结构走插件注册而非改内核」。
+    """
+    if not callable(factory):
+        raise QualityForecastError("主干工厂必须是可调用对象")
+    BACKBONES[name] = factory
+
+
+def _build_backbone(backbone: str, hyperparams: Dict[str, Any]) -> ModelHandle:
+    factory = BACKBONES.get(backbone)
+    if factory is None:
+        raise QualityForecastError(
+            f"未注册的主干类型：{backbone!r}，已注册：{list(BACKBONES)}")
+    return factory(hyperparams)
+
+
+# ---------------------------------------------------------------------------
+# 质量预测模型：固定主干 + 配方加载
+# ---------------------------------------------------------------------------
+
+class QualityForecastModel:
+    """质量预测模型（固定主干 + 配方加载）。
+
+    业务侧两种等价入口：
+
+    1. 直接构造（显式主干）::
+
+         m = QualityForecastModel(backbone="gbdt", hyperparams={...})
+
+    2. 配方加载（推荐，切换模板仅改配方）::
+
+         m = build_from_recipe("templates/.../quality-forecast/recipe.ti.json")
+    """
+
+    def __init__(self, backbone: str = "gbdt",
+                 hyperparams: Optional[Dict[str, Any]] = None,
+                 feature_columns: Optional[Sequence[str]] = None,
+                 target_column: str = "quality_index",
+                 accuracy_floor: float = DEFAULT_ACCURACY_FLOOR):
+        self.recipe_meta: Dict[str, Any] = {
+            "backbone": backbone,
+            "hyperparams": dict(hyperparams or {}),
+            "feature_columns": list(feature_columns or []),
+            "target_column": target_column,
+            "accuracy_floor": accuracy_floor,
+        }
+        self._handle: ModelHandle = _build_backbone(backbone, hyperparams or {})
+
+    @classmethod
+    def from_recipe(cls, recipe: Recipe) -> "QualityForecastModel":
+        """从一个 ``Recipe`` 构造模型（推荐入口）。"""
+        m = cls(
+            backbone=recipe.backbone,
+            hyperparams=recipe.hyperparams,
+            feature_columns=recipe.feature_columns,
+            target_column=recipe.target_column,
+            accuracy_floor=recipe.accuracy_floor,
+        )
+        m.recipe_meta["recipe_name"] = recipe.name
+        m.recipe_meta["industry"] = recipe.industry
+        return m
+
+    # ---- 训练 / 推理 ----
+
+    def fit(self, X: Sequence[Sequence[float]], y: Sequence[float]) -> "QualityForecastModel":
+        self._handle.fit(X, y)
+        return self
+
+    def predict(self, X: Sequence[Sequence[float]]) -> List[float]:
+        return self._handle.predict(X)
+
+    @property
+    def fitted(self) -> bool:
+        return self._handle.fitted
+
+    # ---- 验收口径 ----
+
+    def evaluate(self, X: Sequence[Sequence[float]],
+                 y: Sequence[float]) -> "Accuracy":
+        """评估并返回准确率/MAE/RMSE 与是否达标。
+
+        准确率口径（PRD 5.3 / 里程碑）：相对误差在容忍带
+        ``tolerance``（默认 10%）内计为命中。``accuracy >= accuracy_floor``
+        即视为达标（默认 90%）。
+        """
+        preds = self.predict(X)
+        return Accuracy.compute(
+            y_true=list(y), y_pred=preds,
+            accuracy_floor=self.recipe_meta["accuracy_floor"])
+
+    def to_dict(self) -> Dict[str, Any]:
+        return {
+            "recipe_meta": dict(self.recipe_meta),
+            "handle": self._handle.to_dict(),
+        }
+
+
+# ---------------------------------------------------------------------------
+# 验收：Accuracy
+# ---------------------------------------------------------------------------
+
+@dataclass(frozen=True)
+class Accuracy:
+    """质量预测验收结果（PRD 5.3 准确率口径）。"""
+
+    accuracy: float
+    mae: float
+    rmse: float
+    tolerance: float
+    accuracy_floor: float
+    passed: bool
+
+    def to_dict(self) -> Dict[str, Any]:
+        return {
+            "accuracy": self.accuracy,
+            "mae": self.mae,
+            "rmse": self.rmse,
+            "tolerance": self.tolerance,
+            "accuracy_floor": self.accuracy_floor,
+            "passed": self.passed,
+        }
+
+    @classmethod
+    def compute(cls, y_true: Sequence[float], y_pred: Sequence[float],
+                tolerance: float = 0.10,
+                accuracy_floor: float = DEFAULT_ACCURACY_FLOOR) -> "Accuracy":
+        if len(y_true) != len(y_pred):
+            raise QualityForecastError(
+                f"y_true/y_pred 长度不一致：{len(y_true)} != {len(y_pred)}")
+        if not y_true:
+            raise QualityForecastError("评估数据为空")
+        n = len(y_true)
+        hits = 0
+        abs_err_sum = 0.0
+        sq_err_sum = 0.0
+        for yt, yp in zip(y_true, y_pred):
+            denom = abs(yt) if abs(yt) > 1e-9 else 1.0
+            rel = abs(yp - yt) / denom
+            if rel <= tolerance:
+                hits += 1
+            abs_err_sum += abs(yp - yt)
+            sq_err_sum += (yp - yt) ** 2
+        accuracy = hits / n
+        mae = abs_err_sum / n
+        rmse = math.sqrt(sq_err_sum / n)
+        return cls(
+            accuracy=accuracy, mae=mae, rmse=rmse,
+            tolerance=tolerance, accuracy_floor=accuracy_floor,
+            passed=accuracy >= accuracy_floor,
+        )
+
+
+# ---------------------------------------------------------------------------
+# 配方构建入口 + 样例协议
+# ---------------------------------------------------------------------------
+
+def build_from_recipe(path: str) -> QualityForecastModel:
+    """从 JSON 配方文件加载并构造一个质量预测模型（推荐入口）。
+
+    切换模板仅改配方文件，业务代码零改动——对齐 PRD 5.3 验收口径。
+    """
+    return QualityForecastModel.from_recipe(load_recipe(path))
+
+
+def _samples_dir() -> str:
+    return os.path.join(os.path.dirname(os.path.abspath(__file__)),
+                        "samples", "quality-forecast")
+
+
+def list_sample_recipes() -> List[str]:
+    """列出内置样例配方（树脂 + Ti 两套，验证同框架加载多套配方）。"""
+    d = _samples_dir()
+    if not os.path.isdir(d):
+        return []
+    return sorted(f for f in os.listdir(d) if f.endswith(".json"))
+
+
+def sample_recipe_path(name: str) -> str:
+    """返回样例配方的完整路径。"""
+    if not name.endswith(".json"):
+        name = name + ".json"
+    return os.path.join(_samples_dir(), name)
diff --git a/core/model-framework/samples/quality-forecast/recipe.resin.json b/core/model-framework/samples/quality-forecast/recipe.resin.json
new file mode 100644
index 0000000..2cc3661
--- /dev/null
+++ b/core/model-framework/samples/quality-forecast/recipe.resin.json
@@ -0,0 +1,21 @@
+{
+  "name": "resin-quality",
+  "backbone": "gbdt",
+  "industry": "吸附树脂（已终验化工新材料AI平台 baseline）",
+  "hyperparams": {
+    "n_estimators": 100,
+    "max_depth": 3,
+    "learning_rate": 0.1,
+    "random_state": 7
+  },
+  "feature_columns": [
+    "reactor_temp",
+    "reactor_pressure",
+    "flow_rate",
+    "ph_value",
+    "conversion_rate"
+  ],
+  "target_column": "resin_purity_index",
+  "accuracy_floor": 0.90,
+  "notes": "PRD 5.3 ① 质量预测：树脂纯度/合格率预测，复用已交付化工AI平台 baseline 超参。"
+}
diff --git a/core/model-framework/samples/quality-forecast/recipe.ti.json b/core/model-framework/samples/quality-forecast/recipe.ti.json
new file mode 100644
index 0000000..c733821
--- /dev/null
+++ b/core/model-framework/samples/quality-forecast/recipe.ti.json
@@ -0,0 +1,22 @@
+{
+  "name": "ti-cl4-quality",
+  "backbone": "gbdt",
+  "industry": "海绵钛氯化车间（Template-Ti 一期）",
+  "hyperparams": {
+    "n_estimators": 120,
+    "max_depth": 4,
+    "learning_rate": 0.08,
+    "random_state": 42
+  },
+  "feature_columns": [
+    "furnace_temp",
+    "furnace_pressure",
+    "cl2_flow",
+    "ti_feed_rate",
+    "impurity_fe",
+    "impurity_v"
+  ],
+  "target_column": "ti_product_grade_index",
+  "accuracy_floor": 0.90,
+  "notes": "PRD 5.3 ① 质量预测：氯化车间一次合格率预测，验收准确率≥90%（PRD 第6章里程碑）。一期数据门槛：≥6个月标注（LIMS对接后补标）。"
+}
diff --git a/core/model-framework/tests/__init__.py b/core/model-framework/tests/__init__.py
new file mode 100644
index 0000000..40a96af
--- /dev/null
+++ b/core/model-framework/tests/__init__.py
@@ -0,0 +1 @@
+# -*- coding: utf-8 -*-
diff --git a/core/model-framework/tests/_bootstrap.py b/core/model-framework/tests/_bootstrap.py
new file mode 100644
index 0000000..31a9dcf
--- /dev/null
+++ b/core/model-framework/tests/_bootstrap.py
@@ -0,0 +1,28 @@
+# -*- coding: utf-8 -*-
+"""测试引导：把连字符目录 ``core/model-framework`` 加载为可导入包
+``model_framework``，使测试可 ``from model_framework import ...``。
+
+与仓库内各 core 模块的测试引导同款模式（importlib 完整加载包，执行
+``__init__.py``，保持顶层导出可用）。
+"""
+import importlib.util
+import os
+import sys
+
+PKG_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+REPO_ROOT = os.path.dirname(os.path.dirname(
+    os.path.dirname(os.path.dirname(os.path.abspath(__file__)))))
+
+
+def _load_package(name: str, path: str) -> None:
+    if name in sys.modules:
+        return
+    init_py = os.path.join(path, "__init__.py")
+    spec = importlib.util.spec_from_file_location(
+        name, init_py, submodule_search_locations=[path])
+    module = importlib.util.module_from_spec(spec)
+    sys.modules[name] = module
+    spec.loader.exec_module(module)
+
+
+_load_package("model_framework", PKG_DIR)
diff --git a/core/model-framework/tests/test_quality_forecast.py b/core/model-framework/tests/test_quality_forecast.py
new file mode 100644
index 0000000..395e0fb
--- /dev/null
+++ b/core/model-framework/tests/test_quality_forecast.py
@@ -0,0 +1,255 @@
+# -*- coding: utf-8 -*-
+"""``quality_forecast`` 单元测试（issue #36）。
+
+覆盖：
+- 配方（Recipe）不可变性 / 序列化往返 / 非法主干与越界校验；
+- 主干工厂注册表 + 自定义主干注册（PRD 5.3「新增结构走插件注册」）；
+- stub / gbdt / dnn 三类主干的 fit/predict/evaluate 契约；
+- 固定主干 + 配方加载：同框架加载 Ti / 树脂两套配方均跑通（PRD 5.3
+  验收口径）；
+- Accuracy 验收口径（PRD 5.3 / 里程碑：准确率 ≥ 90%）；
+- 零外部强依赖：无 sklearn 时 stub 退化仍可加载与校验。
+"""
+import json
+import os
+import sys
+import unittest
+
+HERE = os.path.dirname(os.path.abspath(__file__))
+sys.path.insert(0, HERE)
+import _bootstrap  # noqa: E402  注册 model_framework 包
+
+from model_framework import (  # noqa: E402
+    Accuracy,
+    BACKBONES,
+    ModelHandle,
+    QualityForecastError,
+    QualityForecastModel,
+    Recipe,
+    build_from_recipe,
+    dnn_backbone,
+    gbdt_backbone,
+    list_sample_recipes,
+    load_recipe,
+    register_backbone,
+    sample_recipe_path,
+    stub_backbone,
+)
+
+
+def _linear_dataset(n=40, noise=0.0):
+    """构造一个 y ≈ 2*x0 + x1 的可学习数据集（带可选噪声）。"""
+    X, y = [], []
+    for i in range(n):
+        x0 = float(i % 7) + 1.0
+        x1 = float(i % 5) * 0.5 + 0.5
+        yv = 2.0 * x0 + x1 + noise * (i % 3 - 1)
+        X.append([x0, x1])
+        y.append(yv)
+    return X, y
+
+
+class TestRecipe(unittest.TestCase):
+    """配方数据对象与校验。"""
+
+    def test_defaults_and_immutability(self):
+        r = Recipe(name="t")
+        self.assertEqual(r.backbone, "gbdt")
+        self.assertEqual(r.target_column, "quality_index")
+        self.assertAlmostEqual(r.accuracy_floor, 0.90)
+        with self.assertRaises(Exception):
+            r.name = "other"  # frozen
+
+    def test_roundtrip(self):
+        r = Recipe(name="t", backbone="dnn",
+                   hyperparams={"max_iter": 50},
+                   feature_columns=("a", "b"),
+                   target_column="y",
+                   accuracy_floor=0.8, industry="树脂", notes="n")
+        d = r.to_dict()
+        r2 = Recipe.from_dict(d)
+        self.assertEqual(r, r2)
+        # JSON 往返
+        r3 = Recipe.from_dict(json.loads(json.dumps(d)))
+        self.assertEqual(r, r3)
+
+    def test_invalid_backbone_raises(self):
+        with self.assertRaises(QualityForecastError):
+            Recipe(name="t", backbone="svm")
+
+    def test_accuracy_floor_out_of_range(self):
+        with self.assertRaises(QualityForecastError):
+            Recipe(name="t", accuracy_floor=1.5)
+        with self.assertRaises(QualityForecastError):
+            Recipe(name="t", accuracy_floor=-0.1)
+
+    def test_missing_name(self):
+        with self.assertRaises(QualityForecastError):
+            Recipe(name="")
+
+    def test_load_recipe_from_file(self, ):
+        path = sample_recipe_path("recipe.ti.json")
+        r = load_recipe(path)
+        self.assertEqual(r.name, "ti-cl4-quality")
+        self.assertEqual(r.backbone, "gbdt")
+        self.assertIn("furnace_temp", r.feature_columns)
+
+
+class TestBackbones(unittest.TestCase):
+    """主干工厂与注册表。"""
+
+    def test_builtin_backbones_registered(self):
+        for name in ("gbdt", "dnn", "stub"):
+            self.assertIn(name, BACKBONES)
+
+    def test_register_custom_backbone(self):
+        class _Custom(ModelHandle):
+            def __init__(self, p):
+                super().__init__("custom", p)
+                self._v = 1.0
+
+            def _fit_impl(self, X, y):
+                self._v = sum(y) / len(y)
+
+            def _predict_one(self, row):
+                return self._v
+
+        register_backbone("custom_test", lambda p: _Custom(p))
+        m = QualityForecastModel(backbone="custom_test")
+        X, y = _linear_dataset()
+        m.fit(X, y)
+        self.assertEqual(len(m.predict(X)), len(X))
+        # 清理避免污染其它用例
+        BACKBONES.pop("custom_test", None)
+
+    def test_unknown_backbone_raises(self):
+        with self.assertRaises(QualityForecastError):
+            QualityForecastModel(backbone="not_a_backbone")
+
+    def test_stub_predict_is_deterministic(self):
+        h = stub_backbone({})
+        X, y = _linear_dataset()
+        h.fit(X, y)
+        p1 = h.predict(X)
+        p2 = h.predict(X)
+        self.assertEqual(p1, p2)
+        self.assertTrue(all(isinstance(v, float) for v in p1))
+
+    def test_gbdt_factory_runs_with_or_without_sklearn(self):
+        # 无论 sklearn 是否存在都不应报错
+        h = gbdt_backbone({"n_estimators": 20, "max_depth": 2})
+        X, y = _linear_dataset()
+        h.fit(X, y)
+        preds = h.predict(X)
+        self.assertEqual(len(preds), len(y))
+
+
+class TestModelContract(unittest.TestCase):
+    """模型 fit/predict/evaluate 契约。"""
+
+    def test_fit_predict_shapes(self):
+        m = QualityForecastModel(backbone="stub")
+        X, y = _linear_dataset(20)
+        m.fit(X, y)
+        self.assertTrue(m.fitted)
+        preds = m.predict(X)
+        self.assertEqual(len(preds), len(y))
+
+    def test_predict_before_fit_raises(self):
+        m = QualityForecastModel(backbone="stub")
+        with self.assertRaises(QualityForecastError):
+            m.predict([[1.0, 2.0]])
+
+    def test_fit_mismatched_lengths_raises(self):
+        m = QualityForecastModel(backbone="stub")
+        with self.assertRaises(QualityForecastError):
+            m.fit([[1.0], [2.0]], [1.0])
+
+    def test_fit_empty_raises(self):
+        m = QualityForecastModel(backbone="stub")
+        with self.assertRaises(QualityForecastError):
+            m.fit([], [])
+
+    def test_to_dict_roundtrip_meta(self):
+        m = QualityForecastModel(backbone="gbdt",
+                                 hyperparams={"n_estimators": 5},
+                                 feature_columns=["a"],
+                                 target_column="y")
+        d = m.to_dict()
+        self.assertEqual(d["recipe_meta"]["backbone"], "gbdt")
+        self.assertIn("handle", d)
+
+
+class TestAccuracy(unittest.TestCase):
+    """验收口径（PRD 5.3：准确率 ≥ 90%）。"""
+
+    def test_perfect_predictions_pass(self):
+        y = [10.0, 20.0, 30.0, 40.0]
+        acc = Accuracy.compute(y, y, accuracy_floor=0.9)
+        self.assertAlmostEqual(acc.accuracy, 1.0)
+        self.assertAlmostEqual(acc.mae, 0.0)
+        self.assertAlmostEqual(acc.rmse, 0.0)
+        self.assertTrue(acc.passed)
+
+    def test_bad_predictions_fail(self):
+        y_true = [10.0, 20.0, 30.0, 40.0]
+        y_pred = [11.0, 50.0, 5.0, 80.0]  # 大偏差
+        acc = Accuracy.compute(y_true, y_pred, accuracy_floor=0.9)
+        self.assertLess(acc.accuracy, 0.9)
+        self.assertFalse(acc.passed)
+        self.assertGreater(acc.mae, 0.0)
+        self.assertGreater(acc.rmse, 0.0)
+
+    def test_length_mismatch_raises(self):
+        with self.assertRaises(QualityForecastError):
+            Accuracy.compute([1.0, 2.0], [1.0])
+
+    def test_empty_raises(self):
+        with self.assertRaises(QualityForecastError):
+            Accuracy.compute([], [])
+
+    def test_evaluate_end_to_end(self):
+        # stub 主干在确定性、低噪声线性数据上应能给出确定性的验收结果
+        m = QualityForecastModel(backbone="stub", accuracy_floor=0.0)
+        X, y = _linear_dataset(30)
+        m.fit(X, y)
+        acc = m.evaluate(X, y)
+        self.assertIsInstance(acc, Accuracy)
+        self.assertEqual(acc.to_dict()["accuracy_floor"], 0.0)
+
+
+class TestSampleRecipes(unittest.TestCase):
+    """样例协议：同框架加载 Ti / 树脂两套配方均跑通（PRD 5.3 验收口径）。"""
+
+    def test_samples_present(self):
+        names = list_sample_recipes()
+        self.assertIn("recipe.ti.json", names)
+        self.assertIn("recipe.resin.json", names)
+
+    def test_build_from_each_sample_runs(self):
+        for name in ("recipe.ti.json", "recipe.resin.json"):
+            m = build_from_recipe(sample_recipe_path(name))
+            self.assertIn(m.recipe_meta["backbone"], ("gbdt", "dnn", "stub"))
+            # 用配方里声明的特征数构造一份演示数据跑通完整链路
+            feat = m.recipe_meta["feature_columns"]
+            n_feat = len(feat)
+            self.assertGreater(n_feat, 0)
+            X = [[float(i + j) for j in range(n_feat)] for i in range(12)]
+            y = [float(i % 4) + 1.0 for i in range(12)]
+            m.fit(X, y)
+            preds = m.predict(X)
+            self.assertEqual(len(preds), len(y))
+            acc = m.evaluate(X, y)
+            self.assertIsInstance(acc, Accuracy)
+
+    def test_two_recipes_share_same_code(self):
+        """切换模板仅改配方，模型代码零改动（PRD 5.3）。"""
+        m1 = build_from_recipe(sample_recipe_path("recipe.ti.json"))
+        m2 = build_from_recipe(sample_recipe_path("recipe.resin.json"))
+        self.assertEqual(type(m1), type(m2))
+        self.assertNotEqual(m1.recipe_meta.get("recipe_name"),
+                            m2.recipe_meta.get("recipe_name"))
+
+
+if __name__ == "__main__":
+    unittest.main(verbosity=2)