Use explicit layout timestamp probe

docs/modernization/debt.md

@@ -247,6 +247,11 @@ agent or engineer to remove them without reconstructing context from chat.
   and existing file coverage, and `plan_asset_file_load_for_platform` consumes
   that probe instead of owning the `stat` call inline. Injected file-watch or
   storage services still need to own the live probe before the debt closes.
+- 2026-06-12: DEBT-0054 was narrowed again. `LayoutManager::load` now calls the
+  explicit timestamp probe only for platform families that use mtime reloads,
+  then passes the result into the pure `plan_asset_file_load_with_probe`
+  decision. The retained probe still uses local `stat` until injected storage
+  or file-watch services replace it.
 - 2026-06-05: DEBT-0056 was narrowed. `src/asset.h` no longer exposes Android
   SDK types or forward declarations; retained Android asset-manager and asset
   handles are stored as opaque pointers and cast only inside `src/asset.cpp`,

docs/modernization/roadmap.md

@@ -646,6 +646,9 @@ decision used by live canvas cursor requests before retained desktop platform
 cursor bridges continue.
 `pp_platform_api::probe_asset_file_timestamp` now owns the retained asset mtime
 probe used by layout reload planning, with missing/existing file coverage.
+`LayoutManager::load` now consumes that explicit probe plus the pure
+`plan_asset_file_load_with_probe` decision instead of calling the probing
+wrapper directly.
 `pano_cli plan-clipboard-read` and `pano_cli plan-clipboard-write` expose the
 app-core clipboard text decisions used by live clipboard get/set requests
 before retained platform clipboard bridges continue.

src/layout.cpp

@@ -24,10 +24,15 @@ void LayoutManager::create()
 bool LayoutManager::load(const char* path)
 {
     auto abs_path = Asset::absolute(path);
-    const auto file_load = pp::platform::plan_asset_file_load(
-        abs_path,
+    const auto platform_family = pp::platform::current_platform_family();
+    const auto file_probe = pp::platform::platform_uses_asset_file_mtime_reload(platform_family)
+        ? pp::platform::probe_asset_file_timestamp(abs_path)
+        : pp::platform::AssetFileTimestampProbe {};
+    const auto file_load = pp::platform::plan_asset_file_load_with_probe(
+        platform_family,
         m_loaded,
-        m_file_last_write_time);
+        m_file_last_write_time,
+        file_probe);
     if (!file_load.should_read_file)
         return file_load.skipped_load_result;
     m_file_last_write_time = file_load.last_write_time;