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/ia/counties/webster/index.md

@@ -32,7 +32,7 @@ timestamp: "2026-07-03"
 
 # Webster County, IA
 
-County jurisdiction.
+County jurisdiction — 4 officeholders mapped.
 
 ## Demographics (ACS 2023)
 

data/jurisdictions/us/states/ia/counties/webster/municipalities/badger/people/chris-wendell.md

@@ -0,0 +1,39 @@
+---
+type: Person
+title: "Chris Wendell"
+description: "Mayor, Badger, IA"
+role: "Mayor, Badger, IA"
+level: "municipal"
+branch: "executive"
+state: "IA"
+tenure:
+  start: "2026-06-20"
+  current: true
+ids:
+  person: "9a59eae8-2f7c-4e97-a6a5-829bdc5adb8a"
+  office: "5e7432d3-dda0-4d6b-9c4d-827eaa399f8a"
+  tenure: "2079d30e-5fae-4ce1-a7ee-94fe6fa33af8"
+  jurisdiction: "30949352-adf9-4e58-8238-4b8530da3011"
+sources:
+  - field: office
+    source: "Wikidata"
+  - field: tenure
+    source: "Wikidata"
+  - field: jurisdiction
+    source: "Census TIGER 2024"
+confidence: official
+tags: [officeholder, municipal, executive, ia]
+timestamp: "2026-07-04"
+---
+
+# Chris Wendell
+
+Current Mayor, Badger, IA.
+
+## Sources
+
+- office: Wikidata
+- tenure: Wikidata
+- jurisdiction: Census TIGER 2024
+
+Generated from the Atlas officeholders v3 export (2026-07-04).

data/jurisdictions/us/states/ia/counties/webster/municipalities/dayton/people/dave-bills.md

@@ -0,0 +1,39 @@
+---
+type: Person
+title: "Dave Bills"
+description: "Mayor, Dayton, IA"
+role: "Mayor, Dayton, IA"
+level: "municipal"
+branch: "executive"
+state: "IA"
+tenure:
+  start: "2019-12-01"
+  current: true
+ids:
+  person: "4295f467-ce29-4298-a491-7242af1a7245"
+  office: "24681f52-d2ae-431e-8ca4-34cd46b51d51"
+  tenure: "0c44e1f8-28cc-471c-a6a6-c85634c0eada"
+  jurisdiction: "db8bee0b-6110-4c22-beea-c8a5d17ea0d0"
+sources:
+  - field: office
+    source: "Wikidata"
+  - field: tenure
+    source: "Wikidata"
+  - field: jurisdiction
+    source: "Census TIGER 2024"
+confidence: official
+tags: [officeholder, municipal, executive, ia]
+timestamp: "2026-07-04"
+---
+
+# Dave Bills
+
+Current Mayor, Dayton, IA.
+
+## Sources
+
+- office: Wikidata
+- tenure: Wikidata
+- jurisdiction: Census TIGER 2024
+
+Generated from the Atlas officeholders v3 export (2026-07-04).

data/jurisdictions/us/states/ia/counties/webster/municipalities/fort-dodge/people/matt-bemrich.md

@@ -0,0 +1,39 @@
+---
+type: Person
+title: "Matt Bemrich"
+description: "Mayor, Fort Dodge, IA"
+role: "Mayor, Fort Dodge, IA"
+level: "municipal"
+branch: "executive"
+state: "IA"
+tenure:
+  start: "2026-06-20"
+  current: true
+ids:
+  person: "b19403b8-3beb-49e4-ac24-25637823bb9b"
+  office: "947a767a-5675-4967-aa53-8366d4c148a9"
+  tenure: "d3bf8408-9529-4191-932f-44dc807de4c8"
+  jurisdiction: "b9afd063-a1b5-42dd-b8e6-615ffab9c2b2"
+sources:
+  - field: office
+    source: "Wikidata"
+  - field: tenure
+    source: "Wikidata"
+  - field: jurisdiction
+    source: "Census TIGER 2024"
+confidence: official
+tags: [officeholder, municipal, executive, ia]
+timestamp: "2026-07-04"
+---
+
+# Matt Bemrich
+
+Current Mayor, Fort Dodge, IA.
+
+## Sources
+
+- office: Wikidata
+- tenure: Wikidata
+- jurisdiction: Census TIGER 2024
+
+Generated from the Atlas officeholders v3 export (2026-07-04).

data/jurisdictions/us/states/ia/counties/webster/municipalities/gowrie/people/bruce-towne.md

@@ -0,0 +1,39 @@
+---
+type: Person
+title: "Bruce Towne"
+description: "Mayor, Gowrie, IA"
+role: "Mayor, Gowrie, IA"
+level: "municipal"
+branch: "executive"
+state: "IA"
+tenure:
+  start: "2026-06-20"
+  current: true
+ids:
+  person: "0c088b73-a487-4076-be90-e19d28867a82"
+  office: "e08c9c0d-0674-4d2d-bc9c-570ab9a7ba49"
+  tenure: "321a934c-76f1-4314-8e31-296c804cad5f"
+  jurisdiction: "108da001-3a06-44b7-bf49-f4fd36605d46"
+sources:
+  - field: office
+    source: "Wikidata"
+  - field: tenure
+    source: "Wikidata"
+  - field: jurisdiction
+    source: "Census TIGER 2024"
+confidence: official
+tags: [officeholder, municipal, executive, ia]
+timestamp: "2026-07-04"
+---
+
+# Bruce Towne
+
+Current Mayor, Gowrie, IA.
+
+## Sources
+
+- office: Wikidata
+- tenure: Wikidata
+- jurisdiction: Census TIGER 2024
+
+Generated from the Atlas officeholders v3 export (2026-07-04).