pathwayd: HTTP service over internal/pathway · 11/11 smoke gate

Network-callable Mem0-style trace memory at :3217, fronted by gateway
/v1/pathway/*. Closes the ADR-004 wire-up: store substrate landed in
2a6234f, this lands the HTTP surface + [pathwayd] config + acceptance
gate.

Smoke proves the architecturally distinctive properties: Revise →
History walks the predecessor chain backward (audit trail), Retire
excludes from Search default but stays Get-able, AddIdempotent bumps
replay_count without replacing — and all survive kill+restart via
JSONL log replay.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

lakehouse.toml

@@ -12,6 +12,7 @@ ingestd_url  = "http://127.0.0.1:3213"
 queryd_url   = "http://127.0.0.1:3214"
 vectord_url  = "http://127.0.0.1:3215"
 embedd_url   = "http://127.0.0.1:3216"
+pathwayd_url = "http://127.0.0.1:3217"
 
 [storaged]
 bind = "127.0.0.1:3211"
@@ -47,6 +48,12 @@ catalogd_url = "http://127.0.0.1:3212"
 secrets_path = "/etc/lakehouse/secrets-go.toml"
 refresh_every = "30s"
 
+[pathwayd]
+bind = "127.0.0.1:3217"
+# Empty = in-memory only (dev/test). Production sets a path under
+# /var/lib/lakehouse/pathway/state.jsonl so traces survive restart.
+persist_path = ""
+
 [s3]
 endpoint        = "http://localhost:9000"
 region          = "us-east-1"