Use Go rules for Windows filename components

docs/roadmap/remediation.md

@@ -1,6 +1,6 @@
 # Configuration Discovery Review Findings
 
-Status: findings 1–3 complete; findings 4–5 remain open.
+Status: findings 1–4 complete; finding 5 remains open.
 
 Reviewed commit: `e50fee2`, including the discovery implementation commits after
 `424c897`. The review compared the implementation with the
@@ -142,7 +142,14 @@ release procedure; do not introduce native macOS validation as a gate.
 
 ## 4. Use Platform-Aware Windows Component Validation
 
-Priority: P3. Status: open. Algorithmic audit: correctness finding.
+Priority: P3. Status: complete. Algorithmic audit: correctness finding.
+
+**Completed:** Windows validation now delegates reserved-name decisions to
+`filepath.IsLocal` while preserving the selected component/character checks. The
+manual device table was removed. Tests cover console names, platform-dependent
+extension behavior, and invalid later search components; Unix tests retain their
+own filename rules. Focused tests and `./scripts/check.sh` passed on Linux. The
+Windows engine test binary cross-compiled successfully; it was not run natively.
 
 **Location:** [discovery.go](../../internal/engine/discovery.go),
 `validWindowsFilenameComponent`, lines 266–281.
@@ -249,8 +256,8 @@ ordinary file acquisition. It did not benchmark or reopen those choices.
 
 No unplanned quadratic algorithm or other actionable asymptotic regression was
 identified. Findings 4 and 5 record the additional ordinary correctness issues
-found while examining those algorithms; findings 1–3 remain open from the earlier
-review. Existing configuration-tree algorithms outside the discovery changes
+found while examining those algorithms; findings 1–3 were carried forward from
+the earlier review. Existing configuration-tree algorithms outside the discovery changes
 were not re-audited as new feature work.
 
 ## Review Validation
@@ -261,7 +268,7 @@ were not re-audited as new feature work.
 - An external temporary Go program reproduced findings 1 and 2 through the
   public API, comparing explicit file loading with discovery. No production or
   test files were modified for these reproductions.
-- Findings 1–3 remain open despite the existing suites passing.
+- Findings 1–3 remained open at the original review despite the suites passing.
   The broader discovery architecture is implemented: immutable root-owned
   descriptions, incremental ordered selection during shared source acquisition,
   concrete selected-source propagation, and shared absent-input handling before