Municipals: nest 1,823 city officeholders under their real counties

Pull Atlas's place→county crosswalk (Census TIGER 2024 places × county
geometries, 32,041 places) into the build as a committed raw input, and
use it to resolve municipal officeholders whose county was unknown.

- data/place_county_crosswalk.jsonl — new raw input (place_geoid → county_geoid)
- build.py — place-name+state → county_geoid → ACS county slug as a fallback
  in county_slug(); city_slug() generalized to non-FL bare place labels
- data/sources/sources.yaml — provenance entry for the crosswalk

_unresolved municipals: 1919 → 58. The remainder are genuine: CT planning
regions (post-county), county-level rows mislabeled municipal upstream,
consolidated city-counties (null label), Wikidata-QID placeholder names,
and ambiguous same-name places — left unresolved rather than guessed.

Join key is county_geoid (5-digit FIPS); the directory slug is taken from
the ACS county node so municipals nest under the exact existing county dir.
Deterministic (byte-identical rebuild); validate.py passes 19,721 records.

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

data/jurisdictions/us/states/la/counties/east-baton-rouge-parish/index.md

@@ -32,7 +32,7 @@ timestamp: "2026-07-03"
 
 # East Baton Rouge Parish, LA
 
-County jurisdiction.
+County jurisdiction — 2 officeholders mapped.
 
 ## Demographics (ACS 2023)
 

data/jurisdictions/us/states/la/counties/east-baton-rouge-parish/municipalities/baker/people/darnell-waites.md

@@ -0,0 +1,39 @@
+---
+type: Person
+title: "Darnell Waites"
+description: "Mayor, Baker, LA"
+role: "Mayor, Baker, LA"
+level: "municipal"
+branch: "executive"
+state: "LA"
+tenure:
+  start: "2016-04-01"
+  current: true
+ids:
+  person: "535b397c-c1ce-4034-90f3-4778d3c76b6e"
+  office: "a6d4e139-cf7e-4f86-8b9b-bf7e935b3e4f"
+  tenure: "cead3d8b-fc88-4e07-9ed0-cf40afb1999e"
+  jurisdiction: "b291eaeb-f192-4134-9907-f28be897c042"
+sources:
+  - field: office
+    source: "Wikidata"
+  - field: tenure
+    source: "Wikidata"
+  - field: jurisdiction
+    source: "Census TIGER 2024"
+confidence: official
+tags: [officeholder, municipal, executive, la]
+timestamp: "2026-07-04"
+---
+
+# Darnell Waites
+
+Current Mayor, Baker, LA.
+
+## Sources
+
+- office: Wikidata
+- tenure: Wikidata
+- jurisdiction: Census TIGER 2024
+
+Generated from the Atlas officeholders v3 export (2026-07-04).

data/jurisdictions/us/states/la/counties/east-baton-rouge-parish/municipalities/baton-rouge/people/sharon-weston-broome.md

@@ -0,0 +1,39 @@
+---
+type: Person
+title: "Sharon Weston Broome"
+description: "Mayor, Baton Rouge, LA"
+role: "Mayor, Baton Rouge, LA"
+level: "municipal"
+branch: "executive"
+state: "LA"
+tenure:
+  start: "2017-01-02"
+  current: true
+ids:
+  person: "804653d6-0854-4b84-8b16-929b267eb87c"
+  office: "6b42a03f-b90b-4d70-a781-ed985043c4c0"
+  tenure: "c6403fbe-ba23-4427-ad5f-045b38e4ae2f"
+  jurisdiction: "f79dfe39-7ba0-45c1-99c4-08352e8adb67"
+sources:
+  - field: office
+    source: "Wikidata"
+  - field: tenure
+    source: "Wikidata"
+  - field: jurisdiction
+    source: "Census TIGER 2024"
+confidence: official
+tags: [officeholder, municipal, executive, la]
+timestamp: "2026-07-04"
+---
+
+# Sharon Weston Broome
+
+Current Mayor, Baton Rouge, LA.
+
+## Sources
+
+- office: Wikidata
+- tenure: Wikidata
+- jurisdiction: Census TIGER 2024
+
+Generated from the Atlas officeholders v3 export (2026-07-04).