feat(phase21.5/22.1): MirBuilder JsonFrag refactor + FileBox ring-1 + registry tests

Phase 21.5 (AOT/LLVM Optimization Prep)
- FileBox ring-1 (core-ro) provider: priority=-100, always available, no panic path
  - src/runner/modes/common_util/provider_registry.rs: CoreRoFileProviderFactory
  - Auto-registers at startup, eliminates fallback panic structurally
- StringBox fast path prototypes (length/size optimization)
- Performance benchmarks (C/Python/Hako comparison baseline)

Phase 22.1 (JsonFrag Unification)
- JsonFrag.last_index_of_from() for backward search (VM fallback)
- Replace hand-written lastIndexOf in lower_loop_sum_bc_box.hako
- SentinelExtractorBox for Break/Continue pattern extraction

MirBuilder Refactor (Box → JsonFrag Migration)
- 20+ lower_*_box.hako: Box-heavy → JsonFrag text assembly
- MirBuilderMinBox: lightweight using set for dev env
- Registry-only fast path with [registry:*] tag observation
- pattern_util_box.hako: enhanced pattern matching

Dev Environment & Testing
- Dev toggles: SMOKES_DEV_PREINCLUDE=1 (point-enable), HAKO_MIR_BUILDER_SKIP_LOOPS=1
- phase2160: registry opt-in tests (array/map get/set/push/len) - content verification
- phase2034: rc-dependent → token grep (grep -F based validation)
- run_quick.sh: fast smoke testing harness
- ENV documentation: docs/ENV_VARS.md

Test Results
✅ quick phase2034: ALL GREEN (MirBuilder internal patterns)
✅ registry phase2160: ALL GREEN (array/map get/set/push/len)
✅ rc-dependent tests → content token verification complete
✅ PREINCLUDE policy: default OFF, point-enable only where needed

Technical Notes
- No INCLUDE by default (maintain minimalism)
- FAIL_FAST=0 in Bring-up contexts only (explicit dev toggles)
- Tag-based route observation ([mirbuilder/min:*], [registry:*])
- MIR structure validation (not just rc parity)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

benchmarks/baselines/box_create_destroy_small.latest.json

@@ -0,0 +1,12 @@
+{
+  "bench": "box_create_destroy_small",
+  "ts": "2025-11-10T02:23:56+09:00",
+  "host": "DESKTOP-K9SQDG2",
+  "unit": "ms",
+  "warmup": 1,
+  "repeat": 3,
+  "c_ms": 1,
+  "py_ms": 10,
+  "ny_vm_ms": 2116,
+  "ny_aot_ms": 0
+}

benchmarks/baselines/box_create_destroy_small.ndjson

@@ -0,0 +1,24 @@
+{
+  "bench": "box_create_destroy_small",
+  "ts": "2025-11-10T02:12:21+09:00",
+  "host": "DESKTOP-K9SQDG2",
+  "unit": "ms",
+  "warmup": 1,
+  "repeat": 3,
+  "c_ms": 1,
+  "py_ms": 9,
+  "ny_vm_ms": 2115,
+  "ny_aot_ms": 0
+}
+{
+  "bench": "box_create_destroy_small",
+  "ts": "2025-11-10T02:23:56+09:00",
+  "host": "DESKTOP-K9SQDG2",
+  "unit": "ms",
+  "warmup": 1,
+  "repeat": 3,
+  "c_ms": 1,
+  "py_ms": 10,
+  "ny_vm_ms": 2116,
+  "ny_aot_ms": 0
+}

benchmarks/baselines/method_call_only_small.latest.json

@@ -0,0 +1,12 @@
+{
+  "bench": "method_call_only_small",
+  "ts": "2025-11-10T02:24:06+09:00",
+  "host": "DESKTOP-K9SQDG2",
+  "unit": "ms",
+  "warmup": 1,
+  "repeat": 3,
+  "c_ms": 1,
+  "py_ms": 9,
+  "ny_vm_ms": 2091,
+  "ny_aot_ms": 0
+}

benchmarks/baselines/method_call_only_small.ndjson

@@ -0,0 +1,24 @@
+{
+  "bench": "method_call_only_small",
+  "ts": "2025-11-10T02:12:30+09:00",
+  "host": "DESKTOP-K9SQDG2",
+  "unit": "ms",
+  "warmup": 1,
+  "repeat": 3,
+  "c_ms": 1,
+  "py_ms": 12,
+  "ny_vm_ms": 2104,
+  "ny_aot_ms": 0
+}
+{
+  "bench": "method_call_only_small",
+  "ts": "2025-11-10T02:24:06+09:00",
+  "host": "DESKTOP-K9SQDG2",
+  "unit": "ms",
+  "warmup": 1,
+  "repeat": 3,
+  "c_ms": 1,
+  "py_ms": 9,
+  "ny_vm_ms": 2091,
+  "ny_aot_ms": 0
+}

benchmarks/c/bench_box_create_destroy_small.c

@@ -0,0 +1,22 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+// Mirrors benchmarks/bench_box_create_destroy_small.hako
+// Loop 1e4 times: create a tiny string, take length, accumulate, destroy.
+int main(void) {
+    const int N = 10000; // 1e4 iterations
+    long long total = 0;
+    for (int i = 0; i < N; i++) {
+        char *tmp = (char*)malloc(2);
+        if (!tmp) return 2;
+        tmp[0] = 'x';
+        tmp[1] = '\0';
+        total += (long long)strlen(tmp);
+        free(tmp);
+    }
+    // Print total to avoid dead‑code elimination; expected 10000
+    printf("%lld\n", total);
+    return 0;
+}
+

benchmarks/c/bench_method_call_only_small.c

@@ -0,0 +1,17 @@
+#include <stdio.h>
+#include <string.h>
+
+// Mirrors benchmarks/bench_method_call_only_small.hako
+// Loop 5e3 times: take length of preallocated string and accumulate.
+int main(void) {
+    const int N = 5000; // 5e3 iterations
+    const char *s = "nyash";
+    long long total = 0;
+    for (int i = 0; i < N; i++) {
+        total += (long long)strlen(s);
+    }
+    // Print total to avoid dead‑code elimination; expected 25000
+    printf("%lld\n", total);
+    return 0;
+}
+

benchmarks/python/bench_box_create_destroy_small.py

@@ -0,0 +1,17 @@
+#!/usr/bin/env python3
+# Mirrors benchmarks/bench_box_create_destroy_small.hako
+# Loop 1e4 times: create a tiny string, take length, accumulate.
+
+def main():
+    N = 10_000
+    total = 0
+    for _ in range(N):
+        # Force a fresh allocation; avoid literal interning
+        tmp = ''.join(['x'])
+        total += len(tmp)
+    # Print to avoid being optimized away
+    print(total)
+
+if __name__ == "__main__":
+    main()
+

benchmarks/python/bench_method_call_only_small.py

@@ -0,0 +1,15 @@
+#!/usr/bin/env python3
+# Mirrors benchmarks/bench_method_call_only_small.hako
+# Loop 5e3 times: take length of preallocated string and accumulate.
+
+def main():
+    N = 5_000
+    s = "nyash"
+    total = 0
+    for _ in range(N):
+        total += len(s)
+    print(total)
+
+if __name__ == "__main__":
+    main()
+