gen_addresses: per-lane fragment dir; duplicate names are a hard error

ghidra/addresses.d/README.md

@@ -0,0 +1,18 @@
+# Per-lane address fragments
+
+`addresses.json` is a single shared file. When several lanes run concurrently they edit the
+same lines, and three times on 2026-09-08 one lane's `git add` swept another's in-flight
+entries into the wrong commit. Nothing was lost, but authorship and atomicity were.
+
+A lane may instead drop its own file here:
+
+```json
+{ "entries": [ { "name": "...", "addr": "0x...", "convention": "...",
+                 "prototype": "...", "status": "verified", "source": "findings/..." } ] }
+```
+
+Name it after the lane (`lane-d.json`). `tools/gen_addresses.py` merges every fragment in
+sorted order after `addresses.json`. A **duplicate name across files is a hard error**, not
+last-wins — two lanes disagreeing about an address is exactly the thing we must not paper over.
+
+The integrator folds fragments back into `addresses.json` once the lane's work is merged.

tools/gen_addresses.py

@@ -1,10 +1,24 @@
 #!/usr/bin/env python3
 """Emit include/generated/sots_addresses.h for sots-engine from ghidra/addresses.json.
 Only facts (name, RVA, convention, prototype, status) — never decompiler text."""
-import json, os, subprocess, sys, datetime
+import glob, json, os, subprocess, sys, datetime
 root = os.path.join(os.path.dirname(__file__), "..")
 j = json.load(open(os.path.join(root, "ghidra", "addresses.json")))
 base = int(j["image_base"], 16)
+
+# Per-lane fragments. addresses.json is a single shared file, so concurrent lanes kept
+# sweeping each other's in-flight entries into the wrong commit. A lane may instead write
+# ghidra/addresses.d/<lane>.json ({"entries": [...]}) — its own file, no shared-line edits.
+# Fragments are merged here in sorted order; a duplicate name is an error, not a silent
+# last-wins, because two lanes disagreeing about an address is exactly what we must not paper over.
+seen = {e["name"]: "addresses.json" for e in j["entries"]}
+for frag_path in sorted(glob.glob(os.path.join(root, "ghidra", "addresses.d", "*.json"))):
+    frag_name = os.path.basename(frag_path)
+    for e in json.load(open(frag_path))["entries"]:
+        if e["name"] in seen:
+            sys.exit(f"duplicate address entry {e['name']!r}: in {seen[e['name']]} and {frag_name}")
+        seen[e["name"]] = frag_name
+        j["entries"].append(e)
 try: rev = subprocess.check_output(["git","-C",root,"rev-parse","--short","HEAD"]).decode().strip()
 except Exception: rev = "unknown"
 out = [ "// GENERATED — do not edit. Facts about Sword of the Stars.exe (GOG 1.8.1).",