test(claw): kill the three text.t27 mutation survivors

.trinity/seals/claw_ClawText.json

@@ -1,28 +1,28 @@
 {
-  "built_by": "t27c-bootstrap@0.5.2+4ab200073",
+  "built_by": "t27c-bootstrap@0.5.2+9448ab4be",
   "closure": [],
   "config": "gen=c,rust,verilog,zig;tests=zig",
-  "gen_hash_c": "sha256:91762b4b1d04fca688d249cd452eace91ca586e70aee0551c770f84b5da67300",
-  "gen_hash_rust": "sha256:3c2ab4d541e80a7b7ecb335a3bce0ebaac46c1e0e64c67c39468509c98aa9da4",
-  "gen_hash_verilog": "sha256:bad1d4ab44c3cb0be36ce57227762d216b5aa30538d9a9457cfe10b731fdd7d4",
-  "gen_hash_zig": "sha256:d208b808b576f1dbe7b7cc721653deaf2ddcc605a9ef0b82970c19e000f7d0c6",
+  "gen_hash_c": "sha256:b59cbd98a2c2f3973ce97cf39abc9b992a590055a34394a0547a8d0a7ff76758",
+  "gen_hash_rust": "sha256:7c1f327640c4418baa19d847e23ec9d3ac96707b3d8a5ccea0b8f9d860af3492",
+  "gen_hash_verilog": "sha256:1166cfb46959e156cc1d9a03b4994fef8cb7b5b8071528c1793642867a3d3e68",
+  "gen_hash_zig": "sha256:98adafb0eac8bba62c82365c19d1f9d6a718c327917bfc2da761b2a02b7b433b",
   "module": "ClawText",
   "ring": 12,
   "seal_schema": 2,
-  "sealed_at": "2026-10-18T09:41:18Z",
+  "sealed_at": "2026-10-18T23:12:27Z",
   "sealed_by": "t27c-bootstrap@0.5.2",
-  "spec_hash": "sha256:b65da69dff231c61a6d3a48558af9e17af42e1acbe3f4763348f1f0c2f118f21",
+  "spec_hash": "sha256:968755ec1917f766eb2cdd0ab4c0c48aef028a0e7d69e191911695e925b286ad",
   "spec_path": "specs/claw/text.t27",
   "tests": {
     "failed": 0,
     "failing": [],
     "forced": false,
-    "passed": 7,
-    "total": 7,
+    "passed": 9,
+    "total": 9,
     "vacuous": 0
   },
   "toolchain": {
-    "test_runner": "sha256:1982ae948e24d00c5d221ccec12dfce1eb01204b53e37b0f857f93b16d64629d",
+    "test_runner": "sha256:8512b80da533b79289110fca4a65f3336abd7a059ca4b72ea595d5e33ff8ad10",
     "zig": "0.16.0"
   }
 }

specs/claw/text.t27

@@ -175,3 +175,24 @@ test has_prefix_matches_and_rejects {
     assert has_prefix("", 0, "claw-v", 6) == false;
     assert has_prefix("anything", 8, "", 0) == true;
 }
+
+test has_prefix_rejects_a_mismatch_that_fits {
+    // Every reject above is a string shorter than the prefix, so the byte loop's reject was never
+    // reached: a loop that answered true on a mismatch passed (mutation sweep, #10713). These
+    // fit and differ in the first byte, then the last one.
+    assert has_prefix("xlaw-v0.1", 9, "claw-v", 6) == false;
+    assert has_prefix("claw-x0.1", 9, "claw-v", 6) == false;
+    // A string that is exactly the prefix is a prefix: `s_len < p_len` must not become `<=`.
+    assert has_prefix("claw-v", 6, "claw-v", 6) == true;
+}
+
+test put_count_clipped_write_leaves_the_byte_at_cap_alone {
+    // The clip is `w + k < cap`. With `<=` the last digit lands one byte past cap. Only a test
+    // that looks at the byte at cap can tell; the earlier tests never hand in a short cap.
+    var out : [8]u8 = undefined;
+    for i in 0..8 { out[i] = 0; }
+    var w : usize = put_count(&out, 3, 0, 1050);
+    assert w == 4;
+    assert buf_has(&out, 3, "105", 3) == true;
+    assert out[3] == 0;
+}