Merge origin/dev into engram-tiered-storage

Resolve 3 conflicts:
- lang/el-compiler/runtime/el_runtime.c: keep deletion (deprecated runtime fork;
  single-source-of-truth is lang/runtime/, enforced by scripts/check-single-runtime.sh).
- lang/releases/v1.0.0-20260501/el_runtime.h: keep deletion (releases/ is a generated
  artifact folder, not a source path; a release is a git tag, not a folder).
- lang/runtime/el_platform_win.h: union of dev's Windows port (#80: setsockopt optval
  wrapper + curl-less libcurl stubs) and our fsync(->_commit) shim needed by engram_store WAL.

Nothing in dev's build consumes the deprecated fork or releases/ folder.

lang/runtime/el_platform_win.h

@@ -50,6 +50,16 @@
    build defines the same helper as close() so the call sites are identical across platforms. */
 static inline int el_closesocket(SOCKET s) { return closesocket(s); }
 
+/* ── setsockopt optval type ───────────────────────────────────────────────── */
+/* Winsock's setsockopt takes optval as (const char*); POSIX takes (const void*), so el_runtime.c
+   passes &int directly. GCC 14+ makes that an error under -Wincompatible-pointer-types. Wrap it so
+   the runtime's POSIX-style call sites compile unchanged (defined before the macro so the wrapper
+   itself resolves to the real winsock setsockopt). */
+static inline int el_setsockopt(SOCKET s, int level, int optname, const void* optval, int optlen) {
+    return setsockopt(s, level, optname, (const char*)optval, optlen);
+}
+#define setsockopt(s, l, o, v, n) el_setsockopt((s), (l), (o), (v), (int)(n))
+
 /* ── winsock init (once, at load) ─────────────────────────────────────────── */
 static void el__win_net_init(void) {
     static int inited = 0;
@@ -75,6 +85,7 @@ static inline void* el_win_dlsym(void* handle, const char* name) {
 #include <direct.h>            /* _mkdir */
 #define mkdir(path, mode) _mkdir(path)     /* POSIX mkdir(path,mode) → _mkdir(path) */
 #define timegm _mkgmtime                   /* UTC tm → time_t */
+#define fsync(fd) _commit(fd)              /* no fsync() on Windows; _commit() (<io.h>) is the equiv */
 
 /* setenv/unsetenv: not in the Windows CRT; map to _putenv_s / SetEnvironmentVariable. */
 static inline int setenv(const char* name, const char* value, int overwrite) {
@@ -114,4 +125,63 @@ static inline struct tm* gmtime_r(const time_t* t, struct tm* out) {
     return gmtime_s(out, t) == 0 ? out : (struct tm*)0;
 }
 
+/* ── libcurl: degradable stubs for the curl-less Windows build ─────────────── */
+/* The curl-less validation build (WITH_CURL=0) links no libcurl. el_runtime.c uses libcurl
+ * unconditionally for its HTTP client / LLM layer; these stubs let it compile and link so the
+ * runtime, HTTP *server*, graph and memory work natively on Windows. Live outbound HTTP/LLM calls
+ * degrade to a runtime error (curl_easy_perform returns an error) — matching the documented
+ * curl-less contract. When HAVE_CURL is defined (WITH_CURL=1) the real <curl/curl.h> is used and
+ * this whole block is compiled out. POSIX never sees this header, so the POSIX build is untouched. */
+#ifndef HAVE_CURL
+
+typedef void CURL;
+typedef int  CURLcode;
+
+#define CURLE_OK                    0
+#define CURLE_HTTP_RETURNED_ERROR   22
+#define CURL_ERROR_SIZE             256
+
+/* Option ids: values are irrelevant to the no-op setopt below; kept distinct for readability. */
+#define CURLOPT_URL              10002
+#define CURLOPT_WRITEFUNCTION    20011
+#define CURLOPT_WRITEDATA        10001
+#define CURLOPT_POSTFIELDS       10015
+#define CURLOPT_POSTFIELDSIZE      120
+#define CURLOPT_POST                47
+#define CURLOPT_HTTPHEADER       10023
+#define CURLOPT_TIMEOUT_MS         155
+#define CURLOPT_NOSIGNAL            99
+#define CURLOPT_USERAGENT        10018
+#define CURLOPT_FOLLOWLOCATION      52
+#define CURLOPT_ERRORBUFFER      10010
+#define CURLOPT_CUSTOMREQUEST    10036
+#define CURLOPT_FAILONERROR         45
+
+struct curl_slist { char* data; struct curl_slist* next; };
+
+static inline struct curl_slist* curl_slist_append(struct curl_slist* list, const char* s) {
+    struct curl_slist* node = (struct curl_slist*)malloc(sizeof(struct curl_slist));
+    if (!node) return list;
+    node->data = s ? strdup(s) : NULL;
+    node->next = NULL;
+    if (!list) return node;
+    struct curl_slist* p = list;
+    while (p->next) p = p->next;
+    p->next = node;
+    return list;
+}
+static inline void curl_slist_free_all(struct curl_slist* list) {
+    while (list) { struct curl_slist* n = list->next; free(list->data); free(list); list = n; }
+}
+
+static inline CURL* curl_easy_init(void) { return (CURL*)malloc(1); }
+static inline CURLcode curl_easy_setopt(CURL* h, int opt, ...) { (void)h; (void)opt; return CURLE_OK; }
+static inline CURLcode curl_easy_perform(CURL* h) { (void)h; return 7 /* CURLE_COULDNT_CONNECT */; }
+static inline void curl_easy_cleanup(CURL* h) { free(h); }
+static inline const char* curl_easy_strerror(CURLcode c) {
+    (void)c; return "libcurl not built in (curl-less build)";
+}
+
+#endif /* !HAVE_CURL */
+
 #endif /* EL_PLATFORM_WIN_H */