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>

data/jurisdictions/us/states/fl/counties/baker/people/mandi-canaday.md

@@ -7,23 +7,23 @@ level: "county"
 branch: "legislative"
 state: "FL"
 tenure:
+  start: "2025-01-01"
   current: true
-  notes: "Role: District 4"
 ids:
-  person: "0e736af2-6e84-4636-becf-f5264c36b9d5"
-  office: "f2f89012-3d56-4846-9738-6b7820f78d19"
-  tenure: "25103bb5-e4fb-4f41-901f-1a746220000f"
-  jurisdiction: "464e8c76-9412-4145-af24-97aa88936ace"
+  person: "448be7ea-5e11-43e2-9165-560fa89eb525"
+  office: "af4ac3a3-7f02-4500-9b53-338b3762a968"
+  tenure: "2c6fead7-c39f-42a8-aafd-c791a0336d90"
+  jurisdiction: "ca1e649c-bcec-4488-a34b-06a294da784f"
 sources:
   - field: office
-    source: "school-board-scrape-2026-06"
+    source: "FL Division of Elections"
   - field: tenure
-    source: "school-board-scrape-2026-06"
+    source: "FL Division of Elections"
   - field: jurisdiction
-    source: "census-tiger-2024-county"
+    source: "Census TIGER 2024"
 confidence: official
 tags: [officeholder, county, legislative, fl]
-timestamp: "2026-06-20"
+timestamp: "2026-07-04"
 ---
 
 # Mandi Canaday
@@ -32,8 +32,8 @@ Current Baker County School Board (Baker County, FL).
 
 ## Sources
 
-- office: school-board-scrape-2026-06
-- tenure: school-board-scrape-2026-06
-- jurisdiction: census-tiger-2024-county
+- office: FL Division of Elections
+- tenure: FL Division of Elections
+- jurisdiction: Census TIGER 2024
 
-Generated from the Atlas officeholders v2 export (2026-06-20).
+Generated from the Atlas officeholders v3 export (2026-07-04).