fix(#141): strip leading './' from coverage-check paths

Non-git tools (e.g. `find`, `ls`) can emit paths with a "./" prefix.
Without stripping this, "./cmd/foo.go" would not match the glob "cmd/**",
producing a false-positive uncovered-file failure.

Fix: add strings.TrimPrefix(f, "./") after backslash normalization.

Test: TestRunValidateDocmap_DotSlashPrefix

Addresses MINOR finding in review #4175.

cmd/review-bot/validatedocmap.go

@@ -178,6 +178,9 @@ func runValidateDocmap(args []string) int {
 		// Normalize Windows-style backslashes to forward slashes so that
 		// changed-file paths from git on Windows match doc-map globs.
 		f = strings.ReplaceAll(f, "\\", "/")
+		// Strip a leading "./" emitted by non-git tools (e.g. `find`) so that
+		// paths like "./cmd/foo.go" match doc-map globs written as "cmd/**".
+		f = strings.TrimPrefix(f, "./")
 		if !review.FileCoveredByDocMap(cfg, f) {
 			uncovered = append(uncovered, f)
 		}

cmd/review-bot/validatedocmap_test.go

@@ -624,3 +624,28 @@ func TestValidateDocmapPath_NonRegularFile(t *testing.T) {
 		t.Errorf("expected regular-file rejection in stderr, got %q", stderr)
 	}
 }
+
+// TestRunValidateDocmap_DotSlashPrefix verifies that paths emitted with a
+// leading "./" (e.g. from `find` or `ls`) match doc-map globs correctly.
+// Without TrimPrefix, "./cmd/foo.go" would not match the pattern "cmd/**".
+func TestRunValidateDocmap_DotSlashPrefix(t *testing.T) {
+	dir := t.TempDir()
+	makeDocFile(t, dir, "docs/foo.md")
+
+	docmap := makeDocmapInDir(t, dir, `
+mappings:
+  - paths:
+      - "cmd/**"
+    docs:
+      - docs/foo.md
+`)
+
+	// File with a leading "./" should be treated as covered.
+	code, _, stderr := stdinValidateDocmap(t,
+		"./cmd/foo.go\n",
+		[]string{"--docmap", docmap, "--repo-root", dir},
+	)
+	if code != 0 {
+		t.Errorf("expected exit 0 for './' prefixed covered file, got %d; stderr: %q", code, stderr)
+	}
+}