Sync: officeholders v3 — fresh export from live Atlas DB (13,329 tenures)

Re-exported directly from Postgres (10.0.0.116), not Atlas's introspection,
which under-reported the roster (its v3 export had 11,473, missing the
restored Florida League of Cities municipal set). Live DB current tenures:
state 7,561 · municipal 4,009 · county 1,217 · federal 542.

- build.py now reads officeholders-v3.jsonl (was v2); dataset vintage 2026-07-04
- fixed one corrupt start_date at source-export (21021-12-03 -> 2021-12-03,
  Lorraine Borowski, Mayor of Decorah IA)
- scripts/build_viz.py: committed, deterministic generator for the Board's
  county_data.json / county_detail.json (previously built ad-hoc)
- generate_changelog.py: ignore files whose only change is the vintage stamp,
  so the diff reflects government change, not re-export bookkeeping

Person files 11,285 -> 13,329. Non-FL municipal officials (1,903) are in the
tree but not yet county-mappable (place->county crosswalk still NULL).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

scripts/generate_changelog.py

@@ -22,12 +22,37 @@ from collections import defaultdict
 
 PREFIX = "data/jurisdictions/"
 
+# Lines that are pure build bookkeeping, not government facts. A file whose only
+# change is one of these (the dataset-vintage stamp) did NOT change as a mirror
+# of government — it was just re-exported — so it must not surface as a "change".
+# See build.py: the frontmatter `timestamp` and the "Generated from ..." footer.
+BOOKKEEPING = re.compile(
+    r'^\s*timestamp:\s*".*"\s*$'
+    r'|^Generated from the Atlas officeholders v\d+ export \(.*\)\.\s*$')
+
 
 def git(*args):
     return subprocess.run(["git", *args], capture_output=True, text=True,
                           check=True).stdout
 
 
+def bookkeeping_only_files(base, head):
+    """Paths modified ONLY in bookkeeping lines (vintage stamp), to be ignored."""
+    diff = git("diff", "--unified=0", f"{base}..{head}", "--", PREFIX)
+    changed = defaultdict(list)   # path -> list of changed content lines
+    path = None
+    for line in diff.splitlines():
+        if line.startswith("+++ b/"):
+            path = line[6:]
+        elif line.startswith("--- ") or line.startswith("diff ") \
+                or line.startswith("@@") or line.startswith("index "):
+            continue
+        elif path and line and line[0] in "+-":
+            changed[path].append(line[1:])
+    return {p for p, lines in changed.items()
+            if lines and all(BOOKKEEPING.match(ln) for ln in lines)}
+
+
 def classify(path):
     """(entity type, jurisdiction label) from a repo path — fast, no file reads."""
     if not path.startswith(PREFIX):
@@ -84,6 +109,8 @@ def main():
     per_state = defaultdict(lambda: defaultdict(int))
     added_bodies = []
     added_by_state = defaultdict(lambda: defaultdict(int))  # state -> etype -> n added
+    ignore = bookkeeping_only_files(base, head)
+    skipped = 0
 
     for line in status.splitlines():
         parts = line.split("\t")
@@ -92,6 +119,9 @@ def main():
         op = {"A": "added", "M": "modified", "D": "removed", "R": "modified"}.get(code)
         if not op:
             continue
+        if op == "modified" and path in ignore:
+            skipped += 1
+            continue
         etype, juris = classify(path)
         if etype is None:
             continue
@@ -111,6 +141,10 @@ def main():
     out.append("")
     if total == 0:
         out.append("No entity changes in this range — the government, as mirrored, held still.")
+        if skipped:
+            out.append("")
+            out.append(f"*({skipped} files were re-exported with a new vintage stamp "
+                       f"but no government change.)*")
         emit(out, write)
         return 0
 
@@ -155,6 +189,10 @@ def main():
         out.append(f"- **{juris}**: {' '.join(b for b in bits if b)}{types}")
     out.append("")
     out.append(f"*{total} entity changes total.*")
+    if skipped:
+        out.append("")
+        out.append(f"*(Ignored {skipped} files whose only change was the "
+                   f"dataset-vintage stamp — re-export, not a government change.)*")
 
     emit(out, write)
     return 0