Content-addressed computation: freeze → hash → CID → thaw

Hash frozen SX to a content identifier (djb2 → hex). Same state
always produces the same CID. Store by CID, retrieve by CID.

- content-hash: djb2 hash of SX text → hex string
- content-put/get: in-memory content store
- freeze-to-cid: freeze scope → store → return CID
- thaw-from-cid: look up CID → thaw signals
- char-code-at / to-hex primitives for both platforms
- Live demo: counter + name widget, content-address button,
  CID display, restore from CID input, CID history

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

shared/static/scripts/sx-browser.js

@@ -14,7 +14,7 @@
   // =========================================================================
 
   var NIL = Object.freeze({ _nil: true, toString: function() { return "nil"; } });
-  var SX_VERSION = "2026-03-15T00:04:32Z";
+  var SX_VERSION = "2026-03-15T00:16:30Z";
 
   function isNil(x) { return x === NIL || x === null || x === undefined; }
   function isSxTruthy(x) { return x !== false && !isNil(x); }
@@ -5359,6 +5359,44 @@ PRIMITIVES["freeze-to-sx"] = freezeToSx;
 })(); };
 PRIMITIVES["thaw-from-sx"] = thawFromSx;
 
+  // content-store
+  var contentStore = {};
+PRIMITIVES["content-store"] = contentStore;
+
+  // content-hash
+  var contentHash = function(sxText) { return (function() {
+  var hash = 5381;
+  { var _c = range(0, len(sxText)); for (var _i = 0; _i < _c.length; _i++) { var i = _c[_i]; hash = (((hash * 33) + charCodeAt(sxText, i)) % 4294967296); } }
+  return toHex(hash);
+})(); };
+PRIMITIVES["content-hash"] = contentHash;
+
+  // content-put
+  var contentPut = function(sxText) { return (function() {
+  var cid = contentHash(sxText);
+  contentStore[cid] = sxText;
+  return cid;
+})(); };
+PRIMITIVES["content-put"] = contentPut;
+
+  // content-get
+  var contentGet = function(cid) { return get(contentStore, cid); };
+PRIMITIVES["content-get"] = contentGet;
+
+  // freeze-to-cid
+  var freezeToCid = function(scopeName) { return (function() {
+  var sxText = freezeToSx(scopeName);
+  return contentPut(sxText);
+})(); };
+PRIMITIVES["freeze-to-cid"] = freezeToCid;
+
+  // thaw-from-cid
+  var thawFromCid = function(cid) { return (function() {
+  var sxText = contentGet(cid);
+  return (isSxTruthy(sxText) ? (thawFromSx(sxText), true) : NIL);
+})(); };
+PRIMITIVES["thaw-from-cid"] = thawFromCid;
+
 
   // === Transpiled from signals (reactive signal runtime) ===
 
@@ -5757,6 +5795,10 @@ PRIMITIVES["resource"] = resource;
   PRIMITIVES["is-html-tag?"] = function(n) { return HTML_TAGS.indexOf(n) >= 0; };
   PRIMITIVES["make-env"] = function() { return merge(componentEnv, PRIMITIVES); };
 
+  // String/number utilities for content addressing
+  PRIMITIVES["char-code-at"] = function(s, i) { return s.charCodeAt(i); };
+  PRIMITIVES["to-hex"] = function(n) { return (n >>> 0).toString(16); };
+
   // localStorage — defined here (before boot) so islands can use at hydration
   PRIMITIVES["local-storage-get"] = function(key) {
     try { var v = localStorage.getItem(key); return v === null ? NIL : v; }