self-review 2026-08-10: make save/load/persist report real results

route_load was a stub response over the most destructive operation in the
server: engram_load resets the store before parsing, so a readable-but-
malformed snapshot left a hollow graph and the route answered {"ok":true}.
With 37GB of stale dated snapshots in the data dir as restore targets, that
is a live risk. Now returns the real return value plus node/edge counts and
an explicit hollow flag.

route_save discarded engram_save's return the same way; persist_canonical
returned a hardcoded 1, making 'let saved: Int = persist_canonical()' a dead
variable at six durable write paths.

engram/src/server.el

@@ -133,8 +133,11 @@ fn route_text_health(method: String, path: String, body: String) -> String {
 fn persist_canonical() -> Int {
     let dir_raw: String = env("ENGRAM_DATA_DIR")
     let dir: String = if str_eq(dir_raw, "") { "/tmp/engram" } else { dir_raw }
-    engram_save(dir + "/snapshot.json")
-    return 1
+    // (2026-08-10 self-review) This returned a hardcoded 1, which made every
+    // caller's `let saved: Int = persist_canonical()` a dead variable — six
+    // durable write paths each believed they had confirmation of a successful
+    // canonical persist and none of them had any. Propagate the real result.
+    return engram_save(dir + "/snapshot.json")
 }
 
 // INCOMPLETE-ROUTE FIX (2026-07-24 self-review): this route silently dropped
@@ -329,8 +332,15 @@ fn route_save(method: String, path: String, body: String) -> String {
     let dir_raw: String = env("ENGRAM_DATA_DIR")
     let dir: String = if str_eq(dir_raw, "") { "/tmp/engram" } else { dir_raw }
     let p: String = if str_eq(p_raw, "") { dir + "/snapshot.json" } else { p_raw }
-    engram_save(p)
-    "{\"ok\":true,\"path\":\"" + p + "\"}"
+    // (2026-08-10 self-review) engram_save returns 0 on an empty path and the
+    // route discarded it, so the response was a literal "ok":true regardless
+    // of whether anything was written. Report the actual result AND the counts
+    // that were supposed to have been written — the same move that made
+    // route_health honest on 2026-08-01. A caller can now tell "saved 13k
+    // nodes" from "saved nothing and said ok".
+    let sv: Int = engram_save(p)
+    let sv_ok: String = if sv == 0 { "false" } else { "true" }
+    "{\"ok\":" + sv_ok + ",\"path\":\"" + p + "\",\"node_count\":" + int_to_str(engram_node_count()) + ",\"edge_count\":" + int_to_str(engram_edge_count()) + "}"
 }
 
 fn route_load(method: String, path: String, body: String) -> String {
@@ -338,8 +348,29 @@ fn route_load(method: String, path: String, body: String) -> String {
     let dir_raw: String = env("ENGRAM_DATA_DIR")
     let dir: String = if str_eq(dir_raw, "") { "/tmp/engram" } else { dir_raw }
     let p: String = if str_eq(p_raw, "") { dir + "/snapshot.json" } else { p_raw }
-    engram_load(p)
-    ok_json()
+    // (2026-08-10 self-review) This was a stub response over the single most
+    // destructive operation in the server. engram_load returns 0 on an empty
+    // path, an unopenable file, a zero-length file, or malloc failure — and
+    // this route answered ok_json() in every one of those cases.
+    //
+    // Precise failure shape (el_runtime.c:9890): the fopen guard runs BEFORE
+    // the store reset, so a MISSING path is genuinely safe — it returns 0 with
+    // the graph intact. The dangerous case is a readable-but-malformed file:
+    // the reset loop frees every node and edge FIRST, then parses, so a
+    // truncated or non-snapshot JSON leaves a hollow store — and the caller
+    // was told "ok":true. With 37 GB of stale dated snapshots sitting in the
+    // data dir as tempting restore targets, "restore reported success and
+    // silently emptied the graph" is a live risk, not a hypothetical one.
+    //
+    // Fix: surface the return value AND the resulting counts. node_count=0
+    // after a load is the unambiguous hollow-store signal (same convention
+    // route_health adopted 2026-08-01). Callers can now verify a restore
+    // instead of trusting it.
+    let ld: Int = engram_load(p)
+    let ld_ok: String = if ld == 0 { "false" } else { "true" }
+    let nc_after: Int = engram_node_count()
+    let hollow: String = if nc_after == 0 { "true" } else { "false" }
+    "{\"ok\":" + ld_ok + ",\"path\":\"" + p + "\",\"node_count\":" + int_to_str(nc_after) + ",\"edge_count\":" + int_to_str(engram_edge_count()) + ",\"hollow\":" + hollow + "}"
 }
 
 // (2026-08-01 self-review) Health previously returned a hardcoded literal —