fix/test: PR #21 review — guard, safety Bell, api write-back, temp paths

fix(soul): add HTTP-engram guard to safe_to_seed — when ENGRAM_URL is set
the HTTP Engram owns persistence; genesis must never save to local snapshot
regardless of node counts (was: guard_disk forced to empty string, making
the ratio check vacuously true and allowing init_soul_edges+engram_save).

fix(soul): use multiplication form for ratio guard — node_count * 16000 <
disk_len avoids floor-division truncation that underestimated boundary files
(250KB / 16000 = 15.6, floors to 15; a 15-node graph wrongly passed old guard).

fix(chat): add safety_augment_system to handle_chat_as_soul,
handle_dharma_room_turn, and handle_dharma_room_turn_agentic — all three
called the LLM without Hard Bell evaluation, leaving users in dharma rooms
without crisis resource routing.

fix(neuron-api): add api_persisted read-back to handle_api_define_process —
was the only write handler that returned ok:true without verifying the node
was actually written to engram.

fix(routes): unique temp file path in connectd_post — replaces fixed
/tmp/neuron-connectors-req.json with a timestamped path to prevent
collision if concurrency is added or two soul instances share a machine.

test: add tests/test_bell_safety.el — covers safety_detect_bell_level
(none/soft/hard), safety_classify_hard_bell (abuse/self_harm routing),
safety_normalize (smart-quote), safety_augment_system, and
handle_safety_contact_post (validation + read-back).

test: add tests/test_soul_guard.el — pure-function logic tests for the
safe_to_seed predicate: 200KB boundary, 47MB/63-node clobber scenario,
HTTP-engram mode, multiplication vs division truncation at 250KB.

test: add tests/test_api_define_process.el — verifies the define_process
write is read-back verified after the fix.

routes.el

@@ -219,7 +219,9 @@ fn connectd_get(suffix: String) -> String {
 // so arbitrary JSON cannot reach the shell as a command-line argument.
 fn connectd_post(suffix: String, body: String) -> String {
     let eff: String = if str_eq(body, "") { "{}" } else { body }
-    let tmp: String = "/tmp/neuron-connectors-req.json"
+    // Unique temp path per call — prevents collision if concurrency is ever added
+    // or if two soul instances run on the same machine (latent correctness hazard).
+    let tmp: String = "/tmp/neuron-connectors-req-" + int_to_str(time_now()) + ".json"
     fs_write(tmp, eff)
     let out: String = exec_capture("curl -s --max-time 20 -X POST http://127.0.0.1:7771" + suffix + " -H 'Content-Type: application/json' -d @" + tmp)
     if str_eq(out, "") {