runtime: add dharma-required functions to el_runtime.c and runtime/*.el

Add the following functions that dharma registry calls but were missing
from the El runtime:

el_runtime.c (consumed by the old build system via released SDK):
  - list_len, list_get — aliases for el_list_len/el_list_get (handlers.el)
  - json_array_push — append pre-encoded element to JSON array string
  - now_millis, unix_timestamp_ms, time_now_ms — ms-since-epoch aliases
  - log_info, log_warn — structured stderr log helpers
  - config — reads config from environment (alias for getenv)
  - http_patch — HTTP PATCH with Content-Type: application/json
  - http_post_engram — HTTP POST with optional X-API-Key header
  - http_get_engram — HTTP GET with optional X-API-Key header
  - str_to_bytes — encode string as JSON byte array [72,101,...]
  - bytes_to_str — decode JSON byte array back to string
  - hash_sha256 — SHA-256 hex digest using built-in sha256 impl

runtime/*.el (consumed by the new build system):
  - http.el: http_patch, http_post_engram, http_get_engram
  - time.el: now_millis, unix_timestamp_ms, time_now_ms
  - env.el: config, log_info, log_warn, list_len, list_get
  - json.el: json_array_push, bytes_to_str
  - string.el: str_to_bytes, hash_sha256 (via __sha256_hex seed)

el_seed.h / el_seed.c:
  - __sha256_hex primitive with self-contained SHA-256 implementation

runtime/env.el

@@ -63,6 +63,34 @@ fn state_keys() -> String {
     return __state_keys()
 }
 
+// ── DHARMA runtime helpers ─────────────────────────────────────────────────
+
+// config — read a configuration value from the environment.
+// Returns "" if the variable is not set. Alias for env().
+fn config(key: String) -> String {
+    return __env_get(key)
+}
+
+// log_info — write an [INFO] log line to stdout.
+fn log_info(msg: String) {
+    __println("[INFO] " + msg)
+}
+
+// log_warn — write a [WARN] log line to stdout.
+fn log_warn(msg: String) {
+    __println("[WARN] " + msg)
+}
+
+// list_len — return the number of elements in a list. Alias for el_list_len.
+fn list_len(lst: [String]) -> Int {
+    return el_list_len(lst)
+}
+
+// list_get — return the element at index i in a list. Alias for el_list_get.
+fn list_get(lst: [String], i: Int) -> String {
+    return el_list_get(lst, i)
+}
+
 // ── UUID generation ────────────────────────────────────────────────────────
 
 // uuid_new — generate a new random UUID v4.

runtime/http.el

@@ -170,6 +170,35 @@ fn http_response(status: Int, headers_json: String, body: String) -> String {
     return __http_response(status, headers_json, body)
 }
 
+// ── HTTP client — PATCH ───────────────────────────────────────────────────────
+
+// http_patch performs an HTTP PATCH request with Content-Type: application/json.
+fn http_patch(url: String, body: String) -> String {
+    return __http_do("PATCH", url, body, "{\"Content-Type\":\"application/json\"}", el_http_timeout_ms())
+}
+
+// ── HTTP client — Engram variants (optional API key) ──────────────────────────
+//
+// These are used by dharma's db.el to talk to Engram nodes.
+// The key parameter is the X-API-Key header value; pass "" for no auth.
+
+// http_post_engram performs an HTTP POST with Content-Type: application/json
+// and an optional X-API-Key header. If key is "" no auth header is added.
+fn http_post_engram(url: String, key: String, body: String) -> String {
+    if str_eq(key, "") {
+        return __http_do("POST", url, body, "{\"Content-Type\":\"application/json\"}", el_http_timeout_ms())
+    }
+    return __http_do("POST", url, body, "{\"Content-Type\":\"application/json\",\"X-API-Key\":\"" + key + "\"}", el_http_timeout_ms())
+}
+
+// http_get_engram performs an HTTP GET with an optional X-API-Key header.
+fn http_get_engram(url: String, key: String) -> String {
+    if str_eq(key, "") {
+        return __http_do("GET", url, "", "{}", el_http_timeout_ms())
+    }
+    return __http_do("GET", url, "", "{\"X-API-Key\":\"" + key + "\"}", el_http_timeout_ms())
+}
+
 // ── SSE — Server-Sent Events streaming ───────────────────────────────────────
 //
 // Usage pattern for an SSE handler:

runtime/json.el

@@ -157,6 +157,24 @@ fn json_build_array(items: [String]) -> String {
     return result + "]"
 }
 
+// json_array_push — append a pre-encoded JSON element to a JSON array string.
+// elem must be a valid JSON fragment (e.g. "\"foo\"" or "42").
+// Returns a new JSON array string with elem appended.
+// Example: json_array_push("[]", "\"alice\"") -> "[\"alice\"]"
+fn json_array_push(arr: String, elem: String) -> String {
+    let n: Int = json_array_len(arr)
+    if n == 0 {
+        return "[" + elem + "]"
+    }
+    // arr ends with ']'; insert before it
+    let inner_end: Int = str_last_index_of(arr, "]")
+    if inner_end < 0 {
+        return "[" + elem + "]"
+    }
+    let prefix: String = str_slice(arr, 0, inner_end)
+    return prefix + "," + elem + "]"
+}
+
 // json_escape_string — escape a raw string so it can be safely embedded as a
 // JSON string value.
 //
@@ -171,3 +189,25 @@ fn json_escape_string(s: String) -> String {
     let s5: String = str_replace(s4, "\t", "\\t")
     return s5
 }
+
+// ---------------------------------------------------------------------------
+// DHARMA byte decoding
+// ---------------------------------------------------------------------------
+
+// bytes_to_str — decode a JSON array of integer byte values back to a string.
+// "[104,105]" -> "hi"
+// Inverse of str_to_bytes (defined in string.el). Defined here because it
+// depends on json_array_len and json_array_get_string which live in this file.
+fn bytes_to_str(arr: String) -> String {
+    let n: Int = json_array_len(arr)
+    if n == 0 { return "" }
+    let out: String = __str_alloc(n)
+    let i: Int = 0
+    while i < n {
+        let elem: String = json_array_get_string(arr, i)
+        let b: Int = __str_to_int(elem)
+        out = __str_set_char(out, i, b)
+        i = i + 1
+    }
+    return out
+}

runtime/string.el

@@ -876,3 +876,32 @@ fn str_join(parts: [String], sep: String) -> String {
     }
     return result
 }
+
+// ── DHARMA byte encoding (str_to_bytes) ──────────────────────────────────────
+//
+// str_to_bytes — encode a string as a JSON array of unsigned byte values.
+// "hi" -> "[104,105]"
+// Used by db.el to store content in Engram JSON nodes as a byte array.
+// Note: bytes_to_str (the inverse) is defined in json.el because it depends
+// on json_array_get_string which is defined there.
+fn str_to_bytes(s: String) -> String {
+    let n: Int = __str_len(s)
+    if n == 0 { return "[]" }
+    let result: String = "["
+    let i: Int = 0
+    while i < n {
+        let b: Int = __str_char_at(s, i)
+        if i > 0 { result = __str_concat_raw(result, ",") }
+        result = __str_concat_raw(result, __int_to_str(b))
+        i = i + 1
+    }
+    return __str_concat_raw(result, "]")
+}
+
+// ── Cryptographic hashing ─────────────────────────────────────────────────────
+
+// hash_sha256 — return the SHA-256 hex digest of a string.
+// Delegates to the __sha256_hex seed primitive.
+fn hash_sha256(s: String) -> String {
+    return __sha256_hex(s)
+}

runtime/time.el

@@ -400,3 +400,26 @@ fn uuid_new() -> String {
 fn uuid_v4() -> String {
     return __uuid_v4()
 }
+
+// ---------------------------------------------------------------------------
+// DHARMA-compatible aliases — millisecond-precision timestamps.
+//
+// now_millis, unix_timestamp_ms, and time_now_ms all return the same value:
+// milliseconds since the Unix epoch. They exist because different parts of
+// the dharma codebase use different names for the same concept.
+// ---------------------------------------------------------------------------
+
+// now_millis — milliseconds since Unix epoch. Alias for time_now().
+fn now_millis() -> Int {
+    return __time_now_ns() / 1000000
+}
+
+// unix_timestamp_ms — same as now_millis.
+fn unix_timestamp_ms() -> Int {
+    return __time_now_ns() / 1000000
+}
+
+// time_now_ms — same as now_millis.
+fn time_now_ms() -> Int {
+    return __time_now_ns() / 1000000
+}