feat(xce-test-rc-file): task 2.1 add --norc flag to xce_test

Adds struct arguments.norc, a --norc argp option, OPT_NORC (matching
main.c's OPT_PEERS/OPT_CONF_KEEP_N idiom), and its parse_opt case to
test.c. Parsing/recording only -- no wiring into main()'s control flow
or rcfile.c yet (task 2.2).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AgYRU3zDTqNGV5Jk8aiKLg

.kiro/specs/xce-test-rc-file/tasks.md

@@ -17,7 +17,7 @@
   - _Requirements: 1.2, 1.3_
 
 - [ ] 2. Core: xce_test startup integration
-- [ ] 2.1 Add a flag that skips rc-file loading for a single invocation
+- [x] 2.1 Add a flag that skips rc-file loading for a single invocation
   - Register the flag with xce_test's existing command-line option parsing so it is documented in xce_test's own help output
   - When the flag is given, record that rc-file loading should be skipped for this run
   - Observable: xce_test's help output lists the new flag with a description, and invoking xce_test with the flag parses successfully and records the skip state (verified directly, independent of task 2.2's wiring)

src/controller/testsuite/test.c

@@ -667,12 +667,18 @@ static char args_doc[] = "";
 const char* argp_program_version = NULL;
 const char* argp_program_bug_address = BUG_EMAIL;
 
+/* Long-option key (above ASCII to avoid collisions with short opts) --
+ * mirrors src/controller/main.c's OPT_PEERS/OPT_CONF_KEEP_N idiom. */
+#define OPT_NORC 256
+
 struct arguments {
     int verbose;
+    int norc;
 };
 
 static struct argp_option options[] = {
     { "verbose", 'v', 0, 0, "Produce verbose logs" },
+    { "norc", OPT_NORC, 0, 0, "Skip loading the rc file for this invocation" },
     { 0 }
 };
 
@@ -684,6 +690,9 @@ static error_t parse_opt(int key, char* arg, struct argp_state* state)
     case 'v':
         arguments->verbose++;
         break;
+    case OPT_NORC:
+        arguments->norc = 1;
+        break;
     default:
         return ARGP_ERR_UNKNOWN;
     }