feat(tiling): 自适应瓦片规划器 + VLM 分辨率离线标定

背景：逐图框审查固定「整体 + 2x2 象限」截图，大图幅（A0/A1）读不清细节。
改为按**实体分布**自适应决定截几张、截哪里。

- 新增 dwg_review/tiling.py（纯函数）：
  SHEET_SIZES_MM / frame_world_size / frame_scale（sheet_scale>0 用之，否则由
  bbox/纸张反算，否则 default）/ effective_px（与 downsample 同规则）/
  world_per_px / is_text_type（标准名 + 自定义类名含 TEXT/LABEL/DIM/NOTE/TAG/
  ANNO/TITLE）/ cluster_text_flags / tiles_for_box / subdivide / plan_regions
  （文字簇优先、空白区不出图、max_tiles 截断、窗口夹到图框范围）
- 新增 verify_vlm_resolution_offline.py：PIL 合成类图纸图（精确像素字高 +
  可控线间距/线宽/虚线）→ 问 VLM 强约束 JSON → 定 R_text / R_line。
  实测：R_text=12px（黑底；白底 10px）；R_line=6px。
  另：实测该模型**无法可靠计数**（6 条线在 2~10px 间距下答 4/10/4/5/4/4），
  故线条判据改用「1 条 vs 2 条」二选一。
- config 新增 TILING_ENABLED / TEXT_HEIGHT_MM / TEXT_READABLE_PX=12 /
  LINE_READABLE_PX=6 / TILE_MAX_COUNT / TILE_OVERLAP / HEATMAP_CELL_DIV /
  HEATMAP_CLUSTER_DILATE / HEATMAP_MAX_AREA_FRAC；EVIDENCE_DETAIL_TILES 与
  EVIDENCE_MAX_IMAGES 保留作回退路径参数
- llm_client 新增 image_size_b64（测量绘图区实际像素，决定单张覆盖范围）
- phases/evidence.capture_images 支持瓦片规划：先截整体图并测像素 →
  plan_regions 成功用规划窗口，否则退回 sub_windows（行为零变化）；
  末尾始终复位整体视口。collect_frame 传实体/文字 bbox；任一信封
  total>returned（截断）→ 退回固定策略，避免误删有内容的瓦片
- 测试：tests/test_tiling.py（28 项）、tests/test_evidence.py 新增规划路径与
  降级用例、test_config / test_llm_client 补新常量与 image_size_b64；
  全量 283 项全绿

tests/test_tiling.py

@@ -0,0 +1,208 @@
+"""`dwg_review.tiling` 单元测试（纯函数，不依赖 CAD / LLM / Pillow）。"""
+
+from dwg_review import tiling as tl
+
+
+def _frame(bbox, sheet_size="A0", sheet_scale=0.0):
+    return {"bbox": list(bbox), "sheet_size": sheet_size, "sheet_scale": sheet_scale}
+
+
+def _cluster(bbox, count=10):
+    return {"bbox": tuple(float(v) for v in bbox), "cells": [], "count": count}
+
+
+# --- norm_box / frame_bbox --------------------------------------------------
+
+def test_norm_box_valid_and_invalid():
+    assert tl.norm_box([0, 0, 10, 20]) == (0.0, 0.0, 10.0, 20.0)
+    assert tl.norm_box([10, 20, 0, 0]) == (0.0, 0.0, 10.0, 20.0)
+    assert tl.norm_box([1, 2, 3]) is None
+    assert tl.norm_box(None) is None
+    assert tl.norm_box([0, 0, float("nan"), 1]) is None
+
+
+def test_frame_bbox_rejects_degenerate_and_non_dict():
+    assert tl.frame_bbox(_frame((0, 0, 100, 50))) == (0.0, 0.0, 100.0, 50.0)
+    assert tl.frame_bbox(_frame((0, 0, 0, 50))) is None   # 零宽
+    assert tl.frame_bbox(_frame((0, 0, 100, 0))) is None   # 零高
+    assert tl.frame_bbox({"bbox": [1, 2, 3]}) is None
+    assert tl.frame_bbox(None) is None
+
+
+def test_frame_world_size():
+    assert tl.frame_world_size(_frame((0, 0, 100, 50))) == (100.0, 50.0)
+    assert tl.frame_world_size(_frame((0, 0, 0, 0))) == (0.0, 0.0)
+
+
+# --- frame_scale：三条路径 --------------------------------------------------
+
+def test_frame_scale_prefers_sheet_scale():
+    assert tl.frame_scale(_frame((0, 0, 100, 50), sheet_scale=100.0)) == 100.0
+
+
+def test_frame_scale_derived_landscape():
+    # A0 横放：世界 118900 x 84100 → 118900/1189 = 100
+    f = _frame((0, 0, 118900, 84100), sheet_size="A0")
+    assert tl.frame_scale(f) == 100.0
+
+
+def test_frame_scale_derived_portrait():
+    # A0 纵放：世界宽 ↔ 纸高 841
+    f = _frame((0, 0, 84100, 118900), sheet_size="A0")
+    assert tl.frame_scale(f) == 100.0
+
+
+def test_frame_scale_falls_back_to_default():
+    assert tl.frame_scale(_frame((0, 0, 100, 50), sheet_size="ZZ"), default=7.0) == 7.0
+    assert tl.frame_scale(_frame((0, 0, 0, 0)), default=7.0) == 7.0
+    assert tl.frame_scale(None, default=7.0) == 7.0
+
+
+# --- effective_px / world_per_px -------------------------------------------
+
+def test_effective_px_no_resize_when_small():
+    assert tl.effective_px((800, 600), 1280) == (800, 600)
+
+
+def test_effective_px_downsamples_long_edge():
+    # 实测 CAD 绘图区 2110x462 → 长边缩到 1280
+    assert tl.effective_px((2110, 462), 1280) == (1280, 280)
+
+
+def test_effective_px_invalid():
+    assert tl.effective_px(None, 1280) == (0, 0)
+    assert tl.effective_px((0, 100), 1280) == (0, 0)
+    assert tl.effective_px((100, 100), 0) == (100, 100)  # 0 = 不缩放
+
+
+def test_world_per_px():
+    # 1:100、纸面 2mm、VLM 需 10px → 每像素 20 图形单位
+    assert tl.world_per_px(100.0, 2.0, 10.0) == 20.0
+    assert tl.world_per_px(0, 2.0, 10.0) == 0.0
+    assert tl.world_per_px(100.0, 2.0, 0) == 0.0
+
+
+# --- is_text_type -----------------------------------------------------------
+
+def test_is_text_type_standard():
+    for t in ("TEXT", "MTEXT", "ATTRIB", "ATTDEF", "DIMENSION", "text"):
+        assert tl.is_text_type(t) is True
+
+
+def test_is_text_type_custom_keywords():
+    for t in ("AECDLABEL", "AECDDIMTEXT", "MYNOTE", "PARTTAG", "ANNOTATION", "TITLEBLK"):
+        assert tl.is_text_type(t) is True
+
+
+def test_is_text_type_negative():
+    for t in ("AECDBEWPIPE", "LINE", "LWPOLYLINE", "INSERT", "HATCH", "", None, 123):
+        assert tl.is_text_type(t) is False
+
+
+# --- 相交 / 文字簇标记 -------------------------------------------------------
+
+def test_boxes_intersect():
+    assert tl.boxes_intersect((0, 0, 10, 10), (5, 5, 15, 15)) is True
+    assert tl.boxes_intersect((0, 0, 10, 10), (10, 10, 20, 20)) is True  # 接触算相交
+    assert tl.boxes_intersect((0, 0, 10, 10), (11, 11, 20, 20)) is False
+    assert tl.boxes_intersect(None, (0, 0, 1, 1)) is False
+
+
+def test_cluster_text_flags():
+    clusters = [_cluster((0, 0, 10, 10)), _cluster((100, 100, 110, 110))]
+    flags = tl.cluster_text_flags(clusters, [(5, 5, 6, 6)])
+    assert flags == [True, False]
+    assert tl.cluster_text_flags(clusters, []) == [False, False]
+    assert tl.cluster_text_flags([], [(0, 0, 1, 1)]) == []
+
+
+# --- tiles_for_box / subdivide ---------------------------------------------
+
+def test_tiles_for_box_fits_single():
+    assert tl.tiles_for_box((0, 0, 1000, 500), 1000, 500) == (1, 1)
+
+
+def test_tiles_for_box_dense():
+    assert tl.tiles_for_box((0, 0, 2000, 1000), 1000, 500) == (2, 2)
+
+
+def test_tiles_for_box_overlap_increases_count():
+    assert tl.tiles_for_box((0, 0, 1000, 500), 1000, 500, overlap=0.1) == (2, 2)
+
+
+def test_tiles_for_box_invalid():
+    assert tl.tiles_for_box(None, 10, 10) == (1, 1)
+    assert tl.tiles_for_box((0, 0, 0, 0), 10, 10) == (1, 1)
+    assert tl.tiles_for_box((0, 0, 10, 10), 0, 10) == (1, 1)
+
+
+def test_subdivide_row_major_top_first():
+    wins = tl.subdivide((0, 0, 100, 100), 2, 2)
+    assert len(wins) == 4
+    assert wins[0] == {"min_x": 0.0, "min_y": 50.0, "max_x": 50.0, "max_y": 100.0}
+    assert wins[1] == {"min_x": 50.0, "min_y": 50.0, "max_x": 100.0, "max_y": 100.0}
+    assert wins[2] == {"min_x": 0.0, "min_y": 0.0, "max_x": 50.0, "max_y": 50.0}
+    assert wins[3] == {"min_x": 50.0, "min_y": 0.0, "max_x": 100.0, "max_y": 50.0}
+
+
+def test_subdivide_overlap_expands_then_clamps():
+    wins = tl.subdivide((0, 0, 100, 100), 2, 2, overlap=0.1, frame_win=(0, 0, 100, 100))
+    # 每格 50x50，外扩 5 → 左上格：x 0..55（左被夹到 0），y 45..100（上被夹到 100）
+    assert wins[0] == {"min_x": 0.0, "min_y": 45.0, "max_x": 55.0, "max_y": 100.0}
+
+
+# --- plan_regions -----------------------------------------------------------
+
+def test_plan_regions_sparse_single_tile():
+    frame = _frame((0, 0, 1000, 500))
+    clusters = [_cluster((100, 100, 400, 300))]
+    wins = tl.plan_regions(frame, clusters, s_line=10.0, view_px=(100, 50))
+    assert len(wins) == 1
+    assert wins[0]["min_x"] <= 100 and wins[0]["max_x"] >= 400
+
+
+def test_plan_regions_dense_splits():
+    frame = _frame((0, 0, 2000, 1000))
+    clusters = [_cluster((0, 0, 2000, 1000))]
+    wins = tl.plan_regions(frame, clusters, s_line=10.0, view_px=(100, 50))
+    assert len(wins) == 4  # 2x2
+
+
+def test_plan_regions_text_uses_finer_scale():
+    frame = _frame((0, 0, 1000, 500))
+    clusters = [_cluster((0, 0, 1000, 500))]
+    line_only = tl.plan_regions(frame, clusters, s_line=10.0, view_px=(100, 50))
+    text = tl.plan_regions(frame, clusters, text_clusters={0}, s_text=5.0,
+                           s_line=10.0, view_px=(100, 50))
+    assert len(line_only) == 1
+    assert len(text) == 4  # 半径减半 → 2x2
+
+
+def test_plan_regions_text_cluster_prioritized_on_truncation():
+    frame = _frame((0, 0, 4000, 2000))
+    clusters = [_cluster((0, 0, 2000, 1000), count=99),   # 非文字，排前面（输入序）
+                _cluster((2000, 1000, 4000, 2000), count=1)]  # 文字
+    wins = tl.plan_regions(frame, clusters, text_clusters={1},
+                           s_text=10.0, s_line=10.0, view_px=(100, 50), max_tiles=2)
+    assert len(wins) == 2
+    # 文字簇（下标 1，位于右上）应优先出图
+    assert wins[0]["min_x"] >= 2000 and wins[0]["min_y"] >= 1000
+
+
+def test_plan_regions_degrades():
+    frame = _frame((0, 0, 1000, 500))
+    clusters = [_cluster((0, 0, 1000, 500))]
+    assert tl.plan_regions(frame, clusters, s_line=0.0, view_px=(100, 50)) == []
+    assert tl.plan_regions(frame, clusters, s_line=10.0, view_px=(0, 0)) == []
+    assert tl.plan_regions({"bbox": [0, 0, 0, 0]}, clusters, s_line=10.0,
+                           view_px=(100, 50)) == []
+    assert tl.plan_regions(frame, [], s_line=10.0, view_px=(100, 50)) == []
+
+
+def test_plan_regions_clamps_to_frame():
+    frame = _frame((0, 0, 1000, 500))
+    clusters = [_cluster((0, 0, 2000, 1000))]  # 超出图框
+    wins = tl.plan_regions(frame, clusters, s_line=10.0, view_px=(100, 50), max_tiles=4)
+    for w in wins:
+        assert w["min_x"] >= 0 and w["max_x"] <= 1000
+        assert w["min_y"] >= 0 and w["max_y"] <= 500