feat: per-theme Jinja env enables theme-level macro override

Co-Authored-By: Claude Code <noreply@anthropic.com>

app/theme_pro.py

@@ -16,7 +16,21 @@ from markupsafe import Markup
 from .core import sanitize, route_path, THEMES
 
 ROOT=Path(__file__).resolve().parent.parent
-LOADER=Environment(loader=FileSystemLoader(str(ROOT/'themes')),autoescape=select_autoescape(['html','xml']))
+_ENVS={}
+
+def env_for(theme):
+    """Per-theme Jinja env: theme dir first, shared themes/ root as fallback.
+
+    Lets a theme override shared macros (_professional_components.html) while
+    inheriting everything else. Cached: one env per theme across large builds.
+    """
+    env=_ENVS.get(theme)
+    if env is None:
+        theme_dir=ROOT/'themes'/theme
+        search=[str(theme_dir),str(ROOT/'themes')] if theme_dir.is_dir() else [str(ROOT/'themes')]
+        env=Environment(loader=FileSystemLoader(search),autoescape=select_autoescape(['html','xml']))
+        _ENVS[theme]=env
+    return env
 
 TITLES={'product':'产品中心','vehicle':'车型中心','post':'新闻资讯','case':'项目案例','brand':'品牌中心','service':'服务与解决方案'}
 
@@ -186,4 +200,4 @@ def render(theme,site,page,records,mode='detail',listing_items=None,blocks_html=
     if theme not in THEMES:raise ValueError('不是内置专业主题')
     ctx=make_context(site,page,records,mode,listing_items,prepared=prepared)
     ctx.update(custom_blocks=Markup(blocks_html or ''),has_custom=bool(blocks_html),noindex=(ctx['kind']=='notfound'),designer_replace=meta(page).get('layout_mode')=='replace')
-    return LOADER.get_template(theme+'/pro.html').render(**ctx)
+    return env_for(theme).get_template('pro.html').render(**ctx)

tests/test_theme_registry.py

@@ -37,3 +37,20 @@ def test_discover_fails_fast_when_themes_dir_missing(tmp_path, monkeypatch):
     import pytest
     with pytest.raises(RuntimeError, match='themes directory missing'):
         core.discover_themes()
+
+def test_env_for_theme_prefers_theme_dir_then_shared_root():
+    from app import theme_pro
+    env = theme_pro.env_for('industrial')
+    paths = [str(p).replace('\\', '/') for p in env.loader.searchpath]
+    assert paths[0].endswith('themes/industrial')
+    assert paths[1].endswith('themes')
+    # 共享宏库必须仍可解析（回落路径）
+    assert env.get_template('_professional_components.html') is not None
+
+def test_env_for_is_cached_per_theme():
+    from app import theme_pro
+    assert theme_pro.env_for('industrial') is theme_pro.env_for('industrial')
+
+def test_env_for_pro_template_loads_unprefixed():
+    from app import theme_pro
+    assert theme_pro.env_for('industrial').get_template('pro.html') is not None