chore: initialize age-reimpl repo

Reverse-engineering + open reimplementation workspace for Eushully's AGE/SYS4
engine (first target: Himegari). The repo root is age-reimpl/; the original game
install and the extracted ALF data are siblings outside the repo and are never
tracked. build/ (derived corpora) is gitignored and regenerated by the tools.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tools/probe_refs.py

@@ -0,0 +1,76 @@
+"""What do T1/T2/T3 entries point at? Plus: extract XOR-0xFF strings from scripts.
+
+Prints dword windows around table-entry targets, and scans for complement-encoded
+Shift-JIS strings.
+"""
+import struct
+import sys
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parents[2] / "extracted" / "DATA1"
+
+def parse(path):
+    data = path.read_bytes()
+    f = struct.unpack_from("<13I", data, 8)
+    body = data[0x3C:]
+    return data, f, body
+
+def dw(body, i):
+    return struct.unpack_from("<I", body, i * 4)[0]
+
+def try_string(body, i, max_dwords=40):
+    """Try to decode a XOR-0xFF cp932 string starting at dword i."""
+    raw = bytearray()
+    n = 0
+    for j in range(i, min(i + max_dwords, len(body) // 4)):
+        chunk = bytes(b ^ 0xFF for b in body[j*4:(j+1)*4])
+        raw += chunk
+        n += 1
+        if 0 in chunk:
+            break
+    else:
+        return None, 0
+    s = raw.split(b"\0")[0]
+    if len(s) == 0:
+        return "", n
+    try:
+        dec = s.decode("cp932")
+    except UnicodeDecodeError:
+        return None, 0
+    if all(0x20 <= b or b in (0x09,) for b in s):
+        return dec, n
+    return None, 0
+
+def windows(name):
+    data, f, body = parse(ROOT / name)
+    nd = len(body) // 4
+    print(f"\n=== {name} (body {nd} dw, code {f[8]} dw) ===")
+    for label, cnt, off in (("T1", f[7], f[8]), ("T2", f[9], f[10]), ("T3", f[11], f[12])):
+        entries = [dw(body, off + k) for k in range(min(cnt, 6))]
+        print(f" {label}: {cnt} entries -> {[hex(e) for e in entries]}")
+        for e in entries[:4]:
+            ctx = [dw(body, i) for i in range(max(0, e - 2), min(nd, e + 5))]
+            s, _ = try_string(body, e)
+            tag = f"  str@target: {s!r}" if s else ""
+            print(f"   target {e:#x}: [-2..+4] = {[hex(v) for v in ctx]}{tag}")
+
+def scan_strings(name, limit=15, min_len=4):
+    data, f, body = parse(ROOT / name)
+    nd = len(body) // 4
+    print(f"\n=== strings in {name} ===")
+    found = 0
+    i = 0
+    while i < nd and found < limit:
+        s, n = try_string(body, i)
+        if s and len(s) >= min_len:
+            print(f"  [{i:#x}] {s!r}")
+            found += 1
+            i += n
+        else:
+            i += 1
+
+if __name__ == "__main__":
+    for n in ("MENU.BIN", "ADDEXP.BIN", "CALLBACK_LOST.BIN", "ALCHEMY.BIN"):
+        windows(n)
+    scan_strings("MENU.BIN")
+    scan_strings("SC0030.BIN", limit=20, min_len=6)