chore(re): stop committing game assets; captures stay local

Issue #49: the repos carry code, tooling and docs only.

Untracks 143 screenshots, 3 savegame blobs and `tools/re-capture/ob_digits.png`
(a digit-template sheet cut from game frames) -- 146 files, 76.4 MB. They stay
in the working tree and are gitignored, so the pages' relative links still
resolve where the captures exist and nothing ships.

Derived measurements (csv/tsv/txt/log/json/jsonl/npy) are our own numbers, not
game content, and stay tracked -- they are what most claims rest on.

`check-capture-citations` had its contract inverted, and it is the half worth
reading:

  * presence now comes from the WORKING TREE, not `git ls-files`. The assets are
    deliberately untracked, so asking the index would report every screenshot as
    missing and fail all 203 citations.
  * a NEW failure: a game asset that IS tracked. A screenshot that sneaks back
    in is invisible in review -- a binary shows as "Bin 0 -> 1234567 bytes" --
    and is permanent once merged, since removing it later needs a history
    rewrite. So that half has to be loud.

Verified:
  * selftest 8/8, including the new rule
  * scan: 212 present, 212 cited, 0 dangling, 0 tracked  -> exit 0
  * force-add one PNG -> "game assets TRACKED: 1", exit 1, selftest red

⚠️ This does NOT remove the blobs from history; a clone still fetches them.
That needs a filter-repo rewrite and a force-push, which is a separate,
human-run step.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

docs/re/README.md

@@ -18,6 +18,22 @@ A wrong-but-confident note is worse than no note: someone builds on it and the b
 for weeks. Every entry therefore carries an explicit **confidence** and its **evidence**.
 This mirrors the project method — *measure the oracle, never infer; refute before believing.*
 
+### Captures are local-only (issue #49)
+
+The repository carries **code, tooling and docs**. Screenshots and savegame
+blobs are game-derived, so since 2026-09-19 they live in `docs/re/captures/`
+on disk and are **gitignored** — the pages' relative links still resolve on a
+machine that has them, and nothing ships.
+
+Derived measurements (`csv`, `tsv`, `txt`, `log`, `json`, `jsonl`, `npy`) are
+our own numbers rather than game content, and stay tracked — they are what most
+claims here actually rest on.
+
+`tools/re/check-capture-citations` enforces both halves: a cited capture must be
+**present**, and a game asset must **not be tracked**. ⚠️ A fresh clone has no
+captures, so its citations will not resolve until the captures are copied in;
+that is expected, and the checker is a local gate rather than a CI one.
+
 ### Clean-room firewall
 
 - ✅ Allowed: behaviour descriptions, field offsets/types, formulas, state machines,

docs/re/captures/.gitignore

@@ -0,0 +1,13 @@
+# Game-derived assets stay on disk and ship nowhere (issue #49).
+#
+# The pages' relative links still resolve on a machine that has the captures,
+# so the evidence stays followable where it exists — it is simply not committed.
+# `tools/re/check-capture-citations` enforces both halves: a cited capture must
+# be PRESENT here, and an asset must NOT be tracked.
+#
+# Derived measurements (csv, tsv, txt, log, json, jsonl, npy) are our own
+# numbers rather than game content, and remain tracked.
+*.png
+*.jpg
+*.jpeg
+*.bin

tools/re-capture/.gitignore

@@ -0,0 +1,3 @@
+
+# Game-derived digit templates for ob_read.py — pixels from the game (issue #49).
+ob_digits.png

tools/re/check-capture-citations

@@ -10,10 +10,17 @@
 largest thing in the repository, and the one place a file can be added, never
 cited, and never noticed.
 
-Two failures, which are opposites and must not be conflated:
+⚠️ 2026-09-19, issue #49: **game assets are no longer committed.** Screenshots
+and savegame blobs live in the working tree and are gitignored, so the pages'
+relative links still resolve on a machine that has them while nothing ships.
+That inverts half of this check — "is it committed?" became "is it PRESENT?",
+and a NEW failure appeared: an asset that IS tracked. Both are below.
 
-  * a page cites a capture that **is not committed** — a reader following it
+Three failures, which are opposites and must not be conflated:
+
+  * a page cites a capture that **is not present** — a reader following it
     gets nothing. That is an error, exactly as in `check-citations`.
+  * a game asset that **is tracked by git** — issue #49 says it must not be.
   * a capture that **no page cites** — not an error. It may be evidence a page
     should have cited, and deleting on that basis would silently ratify the
     omission. Reported, counted, never failed on.
@@ -65,7 +72,16 @@ def committed() -> tuple[set[str], set[str]]:
     proposed. `tools/port/check-citations` uses the working tree for exactly
     this reason; so does this.
     """
-    files = {l for l in git("ls-files", ROOT).splitlines() if l}
+    # 🔴 NOT `git ls-files`: since #49 the assets are deliberately untracked, so
+    # the index no longer knows they exist. Presence is a question about the
+    # working tree, and asking git would report every screenshot as missing and
+    # fail on all 203 citations.
+    files = set()
+    for dirpath, _dirnames, filenames in os.walk(ROOT):
+        for fn in filenames:
+            if fn == ".gitignore":
+                continue
+            files.add(os.path.join(dirpath, fn).replace(os.sep, "/"))
     dirs = set()
     for f in files:
         parts = f.split("/")
@@ -74,6 +90,24 @@ def committed() -> tuple[set[str], set[str]]:
     return files, dirs
 
 
+ASSET_SUFFIXES = (".png", ".jpg", ".jpeg", ".bin")
+
+
+def tracked_assets() -> list[str]:
+    """Game assets that are committed — forbidden since issue #49.
+
+    The repo carries code, tooling and docs. A screenshot that sneaks back in
+    is invisible in review (a binary shows as "Bin 0 -> 1234567 bytes") and is
+    permanent once merged, because removing it later needs a history rewrite.
+    So this is the half of the check that has to be loud.
+    """
+    out = []
+    for l in git("ls-files").splitlines():
+        if l.lower().endswith(ASSET_SUFFIXES):
+            out.append(l)
+    return out
+
+
 def cited() -> set[str]:
     raw = git("grep", "-rhoE", CITE_ERE, "--", *SEARCH, SELF).splitlines()
     out = set()
@@ -141,7 +175,7 @@ def selftest() -> int:
     real_dir = next(iter(dirs), None)
     real_file = next(iter(files), None)
     if not real_dir or not real_file:
-        print("selftest: 🔴 no captures committed — nothing to test against")
+        print("selftest: 🔴 no captures present — nothing to test against")
         return 2
     cases = [
         ("planted dangling caught", "docs/re/captures/no-such-file-anywhere.png", False),
@@ -168,7 +202,15 @@ def selftest() -> int:
     print("  %-34s %s"
           % ("own fixtures not counted", "🔴 FAILED" if fixture_counted else "ok"))
 
-    ok = gathering_ok and not fixture_counted
+    # 🔴 THE #49 RULE NEEDS ITS OWN TICK. Presence now comes from the working
+    # tree, so a checkout with the captures present looks identical whether or
+    # not they are tracked — only this assertion can tell the difference.
+    stowaways = tracked_assets()
+    print("  %-34s %s%s"
+          % ("no game asset tracked", "ok" if not stowaways else "🔴 FAILED",
+             "" if not stowaways else "  (%d tracked)" % len(stowaways)))
+
+    ok = gathering_ok and not fixture_counted and not stowaways
     for name, path, want in cases:
         got = resolves(path.rstrip(".,;:)`"), files, dirs)
         mark = "ok" if got == want else "🔴 FAILED"
@@ -188,19 +230,33 @@ def main() -> int:
             print(f)
         return 0
 
-    print("captures committed          : %d" % len(files))
+    stowaways = tracked_assets()
+    print("captures present on disk    : %d" % len(files))
     print("  cited by a page or a tool : %d" % (len(files) - len(orphans)))
     print("  cited by nothing          : %d  (reported, not failed —" % len(orphans))
     print("                               an orphan may be evidence a page owes)")
+    rc = 0
     if dangling:
-        print("  🔴 cited but NOT committed: %d" % len(dangling))
+        print("  🔴 cited but NOT present  : %d" % len(dangling))
         for d in dangling:
             print("      %s" % d)
-        print("\n🔴 a reader following those gets nothing. Commit the capture, fix the")
+        print("\n🔴 a reader following those gets nothing. Restore the capture, fix the")
         print("   path, or drop the citation.")
-        return 1
-    print("  🔴 cited but NOT committed: 0")
-    return 0
+        rc = 1
+    else:
+        print("  🔴 cited but NOT present  : 0")
+
+    if stowaways:
+        print("  🔴 game assets TRACKED    : %d  (issue #49 — code, tooling, docs only)" % len(stowaways))
+        for a in stowaways[:10]:
+            print("      %s" % a)
+        if len(stowaways) > 10:
+            print("      … and %d more" % (len(stowaways) - 10))
+        print("\n🔴 run `git rm --cached` on those; they stay on disk and stay ignored.")
+        rc = 1
+    else:
+        print("  🔴 game assets TRACKED    : 0")
+    return rc
 
 
 if __name__ == "__main__":