chore(dbg): add_var 逐行探针 a1..a8（TEMP）

崩点落在形参注册段，而这段里唯一的结构性改动是 VarEntry 加了字段。逐行埋点定位到具体哪一步（esz/cnt 也会打出来，可用于核对 sizeof 是否异常）。

App/lib/core/Gen/VarGenMixin.vp

@@ -288,27 +288,30 @@ novirtual class VarGenMixin:
         """Add a variable to the variable table"""
         if name is None or alloca is None or vars_ptr is None: return 1
         if var_count >= HT.MAX_VARS: return 1
+        VLogger.info("dbg.a1.enter", "TR")
         entry_size: sizet = GenTypes.VarEntry.__sizeof__()
         entry_addr: uint64 = uint64(vars_ptr) + var_count * entry_size
         entry: GenTypes.VarEntry* = GenTypes.VarEntry*(entry_addr)
-        # Deep-copy the variable name into stdlib (survives pool reset): storing the AST Name.id pointer lets
-        # later allocations overwrite it, so find_var's strcmp silently misses and rebuilds a degenerate alloca.
+        VLogger.info(f"dbg.a2.entry esz={entry_size} cnt={var_count}", "TR")
         name_len: sizet = string.strlen(name)
+        VLogger.info(f"dbg.a3.namelen={name_len}", "TR")
         name_copy: bytes = stdlib.malloc(name_len + 1)
         if name_copy is None: return 1
         string.strcpy(name_copy, name)
+        VLogger.info("dbg.a4.copied", "TR")
         entry.Name = name_copy
+        VLogger.info("dbg.a5.name", "TR")
         entry.Alloca = alloca
         entry.Used = 1
-        # Explicitly zero the const flag (do not rely on the entry's zero initialization): set_var_const
-        # sets it to 1 only for real const objects, so zeroing avoids false positives.
         entry.IsConst = 0
-        # 生命期标签显式初始化：未登记 = LIFE_UNKNOWN（保守放行）。
+        VLogger.info("dbg.a6.const", "TR")
         entry.Life = GenTypes.LIFE_UNKNOWN
+        VLogger.info("dbg.a7.life", "TR")
         # P2 willFree 的 entry.Freed **不在这里写**：init_vars 已对整块 memset 清零（见 init_vars），
         # 逐个字段写末端偏移在"结构体刚加字段"时容易踩到；统一依赖整块清零。
         # [S3 dual write] Value-type Spec (alloca.Ty is Ptr(value type), so take its pointee)
         entry.Spec = self._spec_of_var_alloca(alloca)
+        VLogger.info("dbg.a8.spec", "TR")
         return 0
 
     def clear_var_freed(self, symtab: GenTypes.SymbolTable*, name: str) -> int: