fix(linear-static-3d-euler-beam): reject CLI option values

docs/implementation-plans/linear-static-3d-euler-beam-implementation-report.md

@@ -1289,3 +1289,42 @@
   Step 27 can consume only its `physics_evidence` after Step 26 passes.
 - concerns: none; no critical implementation, environment, numerical, or
   upstream-contract blocker remains.
+
+### Step 24 Review Fix Round 1 — option-token output rejection
+
+- review_trigger: the approved CLI contract classifies repeated `--output`
+  and every unknown option as usage error exit 2. The original three-argument
+  parser treated the value position as an arbitrary nonempty path, so an
+  option token could advance into input analysis instead.
+- RED-repeated-option: after adding
+  `{missingInput,"--output","--output"}` to the existing exact
+  `LinearStaticCli.ReturnsEveryExactExitCodeAndOrderedDiagnostic` test,
+  `cmake --build .harness/build --config Debug --target
+  fesa_integration_tests` exited 0 and the focused CTest exited 1. Actual exit
+  was 3 and stderr contained no `cli-usage`, rather than expected exit 2.
+- GREEN-repeated-option: rejecting the literal repeated token made the same
+  focused test pass 1/1.
+- RED-unknown-option: the reviewer then identified the general unknown-option
+  case. Adding `{missingInput,"--output","--bogus"}` before broadening the
+  production condition again produced build exit 0 and focused CTest exit 1;
+  actual exit was 3 with no `cli-usage`.
+- production_fix: explicit output form now requires a nonempty third argument
+  that does not begin with `-`. Both a repeated known option and an unknown
+  option token are rejected before any input or output access, while ordinary
+  output paths retain the approved behavior.
+- GREEN-focused: rebuilding `fesa_integration_tests` exited 0 under `/W4 /WX`;
+  the unchanged exact focused test passed 1/1 with both option cases pinned.
+- independent_review: Critical 0, unresolved Important 0. The reviewer reran
+  exact Step 24 10/10, discovery 83, full 83/83, comparison 176 rows/16
+  metrics passed, and reference diff/status clean.
+- remaining_minor: the test-only comparator independently pins float64 result
+  file types but relies on the Step 23 writer self-check/full-suite schema test
+  for exact uint64 endianness and every compound member file dtype/UTF-8. This
+  is defense-in-depth negative coverage, not a reproducible approved-pipeline
+  false pass.
+- remaining_minor: the inherited diagnostic sorter is not a literal
+  implementation of future multi-source declaration/internal-ID ordering, but
+  no V0 single-input CLI misordering is reproducible.
+- remaining_minor: the Step 23 `libmmd.dll` guard remains unconditional across
+  alternate HDF5 targets; it is correct for the approved shared-HDF5
+  environment and is an external portability limitation.

phases/linear-static-3d-euler-beam/index.json

@@ -200,7 +200,7 @@
       "status": "completed",
       "started_at": "2026-08-09T22:13:49+0900",
       "completed_at": "2026-08-09T22:54:33+0900",
-      "summary": "Exact factorize-before-load single-step lifecycle과 argv0-excluded fesa.exe 0/2/3/4/5/6 CLI를 구현하고 read-only legacy B33/HDF5 comparator로 176 rows, 16 metrics, deterministic JSON/physics evidence를 생성해 Step24 10/10 및 전체 83/83을 검증함"
+      "summary": "Exact factorize-before-load single-step lifecycle과 argv0-excluded fesa.exe 0/2/3/4/5/6 CLI를 구현하고 repeated/unknown option token을 usage로 거부하며 read-only legacy B33/HDF5 comparator로 176 rows, 16 metrics, deterministic JSON/physics evidence를 생성해 Step24 10/10 및 전체 83/83을 검증함"
     },
     {
       "step": 25,

src/fesa/app/fesa_application.cpp

@@ -83,7 +83,8 @@ int FesaApplication::run(const std::vector<std::string>& arguments) {
         !arguments[0U].empty() &&
         !startsWithOption(arguments[0U]) &&
         arguments[1U] == "--output" &&
-        !arguments[2U].empty();
+        !arguments[2U].empty() &&
+        !startsWithOption(arguments[2U]);
     if (!defaultOutputForm && !explicitOutputForm) {
         writeDiagnostics({usageDiagnostic()});
         return kUsageExitCode;

tests/integration/app/fesa_application_test.cpp

@@ -332,7 +332,10 @@ TEST(LinearStaticCli, ReturnsEveryExactExitCodeAndOrderedDiagnostic) {
     const auto usage = runApplication({});
     const auto missingInput = directory.path() / "missing.inp";
     const auto input = runApplication({missingInput.string()});
-    const auto repeatedInput = runApplication({missingInput.string()});
+    const auto repeatedOutput = runApplication(
+        {missingInput.string(), "--output", "--output"});
+    const auto unknownOutputOption = runApplication(
+        {missingInput.string(), "--output", "--bogus"});
     const auto model = runApplication(explicitOutputArguments(
         modelInput, directory.path() / "model-failure.h5"));
     const auto solver = runApplication(explicitOutputArguments(
@@ -353,8 +356,14 @@ TEST(LinearStaticCli, ReturnsEveryExactExitCodeAndOrderedDiagnostic) {
     expectDiagnosticFieldOrder(model.standardError);
     expectDiagnosticFieldOrder(solver.standardError);
     expectDiagnosticFieldOrder(output.standardError);
-    EXPECT_EQ(repeatedInput.exitCode, 3);
-    EXPECT_EQ(repeatedInput.standardError, input.standardError);
+    EXPECT_EQ(repeatedOutput.exitCode, 2);
+    expectDiagnosticFieldOrder(repeatedOutput.standardError);
+    EXPECT_NE(repeatedOutput.standardError.find("code=cli-usage"),
+              std::string::npos);
+    EXPECT_EQ(unknownOutputOption.exitCode, 2);
+    expectDiagnosticFieldOrder(unknownOutputOption.standardError);
+    EXPECT_NE(unknownOutputOption.standardError.find("code=cli-usage"),
+              std::string::npos);
 }
 
 TEST(LinearStaticCli, OutputRequestsDoNotFilterMandatoryResults) {