Move SSD truth cell IDs to typed Kotlin

ober

e30d1e6b5a3b88a29a7b61f17f054db340171c96

diff --git a/.build.yml b/.build.yml
index 150bdd8..429b202 100644
--- a/.build.yml
+++ b/.build.yml
@@ -5,7 +5,7 @@ packages:
   - make=4.4.1-r4
 sources:
   # Build dependency: full immutable commit, mirrored in dependencies.lock.json.
-  - "https://git.sr.ht/~lisp/jerboa#c0e0f09a8e0082c2c2aeb08c5dfcac44dbc82bb3"
+  - "https://git.sr.ht/~lisp/jerboa#6fd51087d62a40f8d59ee556da023971a99792b0"
   # The second source is the build subject selected by the SourceHut submitter.
   - https://git.sr.ht/~lisp/jerboa-android
 tasks:
@@ -14,6 +14,6 @@ tasks:
       test "$(apk info -v chez-scheme)" = chez-scheme-10.3.0-r2
       test "$(apk info -v git)" = git-2.54.0-r0
       test "$(apk info -v make)" = make-4.4.1-r4
-      test "$(git -C ../jerboa rev-parse HEAD)" = c0e0f09a8e0082c2c2aeb08c5dfcac44dbc82bb3
-      test "$(git -C ../jerboa rev-parse 'HEAD^{tree}')" = 2e133170b097ee5b7857677a2d087d592439296b
+      test "$(git -C ../jerboa rev-parse HEAD)" = 6fd51087d62a40f8d59ee556da023971a99792b0
+      test "$(git -C ../jerboa rev-parse 'HEAD^{tree}')" = 832ff5f75d3f1ae470789de02f5fd7fbd357e90c
       JERBOA="chez --libdirs .:../jerboa/lib --script" make test
diff --git a/dependencies.lock.json b/dependencies.lock.json
index 2d4f1db..8674b8e 100644
--- a/dependencies.lock.json
+++ b/dependencies.lock.json
@@ -11,8 +11,8 @@
   "generator_runtime": {
     "name": "jerboa",
     "repository": "https://git.sr.ht/~lisp/jerboa",
-    "commit": "c0e0f09a8e0082c2c2aeb08c5dfcac44dbc82bb3",
-    "tree": "2e133170b097ee5b7857677a2d087d592439296b"
+    "commit": "6fd51087d62a40f8d59ee556da023971a99792b0",
+    "tree": "832ff5f75d3f1ae470789de02f5fd7fbd357e90c"
   },
   "assurance_tools": {
     "osv_scanner": {
diff --git a/scripts/verify-supply-chain.sh b/scripts/verify-supply-chain.sh
index b63a301..1dc7d6e 100755
--- a/scripts/verify-supply-chain.sh
+++ b/scripts/verify-supply-chain.sh
@@ -3,8 +3,8 @@ set -eu
 
 repo=$(CDPATH= cd -- "$(dirname -- "$0")/.." && pwd -P)
 lock="$repo/dependencies.lock.json"
-jerboa_commit=c0e0f09a8e0082c2c2aeb08c5dfcac44dbc82bb3 # gitsafe:ignore
-jerboa_tree=2e133170b097ee5b7857677a2d087d592439296b # gitsafe:ignore
+jerboa_commit=6fd51087d62a40f8d59ee556da023971a99792b0 # gitsafe:ignore
+jerboa_tree=832ff5f75d3f1ae470789de02f5fd7fbd357e90c # gitsafe:ignore
 gradle_sha=20f1b1176237254a6fc204d8434196fa11a4cfb387567519c61556e8710aed78
 jdk_macos_sha=8fa1eff40bb637a33613b2ccb8b12c70dc3661cc22cf8e784943715769a05336
 jdk_linux_sha=d8afc263758141a66e0e3aafc321e783f7016696f4eaea067d340a269037d331
diff --git a/templates/ssd-review.ss b/templates/ssd-review.ss
index ab306ee..2809fb8 100644
--- a/templates/ssd-review.ss
+++ b/templates/ssd-review.ss
@@ -2313,6 +2313,35 @@
                   (json-object-put-json-object! cached "source" source)
                   cached)))))))
 
+    (typed-kotlin-file "com/sfb/ssdreview/TruthCellIds.kt"
+      (typed-library (com sfb ssdreview)
+        (export uniqueTruthCellId)
+        (type Int32)
+        (def (truthCellIdBase (groupId : String) (originalId : String)) : String
+          (string-replace-regex
+            (string-append
+              "truth_"
+              (string-append groupId (string-append "_" originalId)))
+            "[^A-Za-z0-9_]"
+            "_"))
+        (def (uniqueTruthCellIdAtIndex (base : String)
+                                       (usedIds : (Set String))
+                                       (index : Int32)) : String
+          (let ((candidate
+                  (if (= index (int32 0))
+                      base
+                      (string-append base (string-append "_" (int32->string index))))))
+            (if (set-contains? usedIds candidate)
+                (uniqueTruthCellIdAtIndex base usedIds (+ index (int32 1)))
+                candidate)))
+        (def (uniqueTruthCellId (groupId : String)
+                                (originalId : String)
+                                (usedIds : (Set String))) : String
+          (uniqueTruthCellIdAtIndex
+            (truthCellIdBase groupId originalId)
+            usedIds
+            (int32 0)))))
+
     (typed-kotlin-file "com/sfb/ssdreview/PathSafety.kt"
       (typed-library (com sfb ssdreview)
         (export safePathComponent safeLeaf safeZipEntryName validSourceKey validatedSourceKey)
@@ -5607,17 +5636,6 @@
        "        group.cellIds.addAll(remappedIds)"
        "    }"
        ""
-       "    private fun uniqueTruthCellId(groupId: String, originalId: String, usedIds: Set<String>): String {"
-       "        val base = \"truth_${groupId}_${originalId}\".replace(Regex(\"\"\"[^A-Za-z0-9_]\"\"\"), \"_\")"
-       "        var candidate = base"
-       "        var index = 1"
-       "        while (usedIds.contains(candidate)) {"
-       "            candidate = \"${base}_$index\""
-       "            index += 1"
-       "        }"
-       "        return candidate"
-       "    }"
-       ""
        "    private fun writeRemoteTruth("
        "        truth: JSONObject,"
        "        modified: Long,"