docs(vault): the census was lying; corrected, and the honest result is flat docs

`scripts/port-census.py` built its corpus from the new directory, so each page
under test was held by itself: every era page reported 0 orphan lines. With the
corpus excluding the file under test, each candidate holds 14-63 sole-record
lines, so no era page is padding and none was trashed.

Deletions of restatement only:
- Multi-Node Runtimes.md (-257): restated launch material owned by
  Qwen3.8 PP Deployment.md; index rows and two Related bullets repointed.
- log.md: 66 headings folded into 35 dated entries (one entry per date, newest
  first), titled headings kept as `date — Title` per the spec's wording, and 78
  lines of transient deploy chatter dropped where every fact token in the line
  is held by an owner page (preserved in .AGENTTRASH/20261019-log-transient/).
- Authentic: the 5-page split reverted (-93); the parent carries
  `okf-exempt: length` and the three stub pages stay deleted.

check-okf.py accepts `## YYYY-MM-DD — Title`; port-census.py excludes the file
under test and gained a docstring note about the trap. One-off compaction tool
moved to ~/.AGENTTRASH. Full suite: 451 tests pass, 0 OKF violations,
155 pages, 0 unresolved links.

scripts/port-census.py

@@ -50,23 +50,39 @@ def held(tok, corpus):
 
 def main(argv):
     new_dir = pathlib.Path(argv[1])
-    corpus = [
-        p.read_text(errors="replace")
-        for p in new_dir.rglob("*.md")
-        if ".AGENTTRASH" not in str(p) and ".obsidian" not in str(p)
-    ]
-    blob = "\n".join(corpus)
-    lost = 0
-    checked = 0
+
+    def corpus_excluding(exclude):
+        """Every vault page except the one under test.
+
+        The corpus is what must still hold a fact AFTER the file is gone, so a
+        file that lives inside the scanned directory has to be removed from it —
+        otherwise every token is "held" by the file itself and the census proves
+        nothing (it reports 0 losses for every page, which is the bug this
+        guards).
+        """
+        out = []
+        for p in new_dir.rglob("*.md"):
+            s = str(p)
+            if ".AGENTTRASH" in s or ".obsidian" in s:
+                continue
+            if exclude is not None and p.resolve() == exclude:
+                continue
+            out.append(p.read_text(errors="replace"))
+        return out
+
+    lost = checked = 0
     for spec in argv[2:]:
         if spec.startswith("git-"):
             ref, path = spec[4:].split(":", 1)
             old = subprocess.run(["git", "show", f"{ref}:{path}"],
                                  capture_output=True, text=True).stdout
             label = f"{ref}:{path}"
+            exclude = None
         else:
             old = pathlib.Path(spec).read_text(errors="replace")
             label = spec
+            exclude = pathlib.Path(spec).resolve()
+        blob = "\n".join(corpus_excluding(exclude))
         for line in old.splitlines():
             s = line.strip().strip("->*|# ").strip()
             if len(s) < 30 or s.startswith("```"):