补充 OPFS 会话默认路径覆盖

结论：Node OPFS smoke 现在验证 INI 缺失参数文件和刀具表文件名时，会话桥接回落到 host path model 默认路径，保持文件边界策略不进入 CNC 语义。

wasm-port/docs/compatibility-validation.md

@@ -110,6 +110,7 @@ parameter semantics, and that INI-derived machine file names are still
 rejected by the OPFS path model when they contain traversal or nested path
 segments. The same Node smoke also validates that explicit session file-name
 options take precedence over INI-derived parameter and tool-table file names,
+and that missing INI file-name values fall back to the host path model defaults,
 keeping host override policy outside CNC semantics.
 
 The browser INI/OPFS smoke script serves `wasm-port/` over localhost and runs
@@ -273,7 +274,8 @@ derived from vendored LinuxCNC INI boolean parsing, INI-derived
 `[RS274NGC]PARAMETER_FILE` and `[EMCIO]TOOL_TABLE` file names mapped to OPFS
 machine files, OPFS path-model rejection of invalid INI-derived file names,
 explicit host session file-name overrides taking precedence over INI-derived
-names, session snapshot custom filename handling plus envelope/path rejection
+names, default host path fallback when INI file-name values are absent,
+session snapshot custom filename handling plus envelope/path rejection
 for unsupported format/version, wrong session id, and invalid snapshot
 filenames, and a browser interpreter smoke that uses the same session bridge
 with real LinuxCNC INI WASM parsing before saving OPFS-backed parameter and