chore(dbg): 临时阶段日志定位 Phase A 崩溃点（定位后移除）

四个探针：PhaseA translating <path> / vpi.gen <rel_path> / TR.enter sha1 / TR.prelude.done。用于把崩溃点夹在 解析→vpi生成→模块前言→函数体翻译 四段之间。

App/lib/Stub/StubGen/Converter.vp

@@ -659,8 +659,10 @@ def _PyiClass(buf: bytes, buf_size: sizet, pos: sizet, cls: ast.ClassDef*, inden
 
 # _GeneratePyiFromAst - walk the AST Module and emit .vpi stub content into buf.
 # Returns bytes written (0 on failure); rel_path should be absolute for error attribution.
-def _GeneratePyiFromAst(mb: memhub.MemBuddy*, tree: ast.AST*, rel_path: str, buf: bytes, buf_size: sizet) -> sizet:
-    """Generate .vpi stub content from an AST into buf"""
+def _GeneratePyiFromAst(mb: memhub.MemBuddy*, tree: ast.AST*, rel_path: str, buf: bytes, buf_size: sizet) -> sizet:
+    """Generate .vpi stub content from an AST into buf"""
+    # [TEMP dbg] 阶段日志：进入 vpi 生成（定位崩溃点，定位后移除）
+    VLogger.info(f"vpi.gen: {rel_path}", "StubGen")
     if tree is None or buf is None or buf_size == 0: return 0
 
     # Error attribution: point "current file" at the file being stubbed. Callers must pass