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/oh/counties/warren/index.md

@@ -32,7 +32,7 @@ timestamp: "2026-07-03"
 
 # Warren County, OH
 
-County jurisdiction.
+County jurisdiction — 3 officeholders mapped.
 
 ## Demographics (ACS 2023)
 

data/jurisdictions/us/states/oh/counties/warren/municipalities/franklin/people/brent-centers.md

@@ -0,0 +1,39 @@
+---
+type: Person
+title: "Brent Centers"
+description: "Mayor, Franklin, OH"
+role: "Mayor, Franklin, OH"
+level: "municipal"
+branch: "executive"
+state: "OH"
+tenure:
+  start: "2026-06-20"
+  current: true
+ids:
+  person: "68143a1d-94c8-4977-8ba6-c6cdd857f75e"
+  office: "09af7123-1f83-4f03-b0d4-d95f5e3c45de"
+  tenure: "aeb75806-86e9-4aed-8ff0-495662f94b9b"
+  jurisdiction: "97ad1552-02f3-4fa9-af91-52027c10b37a"
+sources:
+  - field: office
+    source: "Wikidata"
+  - field: tenure
+    source: "Wikidata"
+  - field: jurisdiction
+    source: "Census TIGER 2024"
+confidence: official
+tags: [officeholder, municipal, executive, oh]
+timestamp: "2026-07-04"
+---
+
+# Brent Centers
+
+Current Mayor, Franklin, OH.
+
+## Sources
+
+- office: Wikidata
+- tenure: Wikidata
+- jurisdiction: Census TIGER 2024
+
+Generated from the Atlas officeholders v3 export (2026-07-04).

data/jurisdictions/us/states/oh/counties/warren/municipalities/lebanon/people/mark-messer.md

@@ -0,0 +1,39 @@
+---
+type: Person
+title: "Mark Messer"
+description: "Mayor, Lebanon, OH"
+role: "Mayor, Lebanon, OH"
+level: "municipal"
+branch: "executive"
+state: "OH"
+tenure:
+  start: "2026-06-20"
+  current: true
+ids:
+  person: "70d7d076-659c-4240-b26b-5eeb7d85ab43"
+  office: "4e4f1a88-7401-4e97-bf2a-660a674eaadc"
+  tenure: "963177c2-118a-4625-9087-f48f47e8b9ff"
+  jurisdiction: "ed013038-3498-403f-8fbd-5866c13f1a4d"
+sources:
+  - field: office
+    source: "Wikidata"
+  - field: tenure
+    source: "Wikidata"
+  - field: jurisdiction
+    source: "Census TIGER 2024"
+confidence: official
+tags: [officeholder, municipal, executive, oh]
+timestamp: "2026-07-04"
+---
+
+# Mark Messer
+
+Current Mayor, Lebanon, OH.
+
+## Sources
+
+- office: Wikidata
+- tenure: Wikidata
+- jurisdiction: Census TIGER 2024
+
+Generated from the Atlas officeholders v3 export (2026-07-04).

data/jurisdictions/us/states/oh/counties/warren/municipalities/springboro/people/john-agenbroad.md

@@ -0,0 +1,39 @@
+---
+type: Person
+title: "John Agenbroad"
+description: "Mayor, Springboro, OH"
+role: "Mayor, Springboro, OH"
+level: "municipal"
+branch: "executive"
+state: "OH"
+tenure:
+  start: "2026-06-20"
+  current: true
+ids:
+  person: "f2087513-9bd6-457f-b2e0-9ba7ca417e9e"
+  office: "55395802-40bd-4557-97e9-2a12431cb5b9"
+  tenure: "453d3962-0857-4061-93bd-60e389722739"
+  jurisdiction: "7be832be-7c22-4d56-969c-ed7913ff4a54"
+sources:
+  - field: office
+    source: "Wikidata"
+  - field: tenure
+    source: "Wikidata"
+  - field: jurisdiction
+    source: "Census TIGER 2024"
+confidence: official
+tags: [officeholder, municipal, executive, oh]
+timestamp: "2026-07-04"
+---
+
+# John Agenbroad
+
+Current Mayor, Springboro, OH.
+
+## Sources
+
+- office: Wikidata
+- tenure: Wikidata
+- jurisdiction: Census TIGER 2024
+
+Generated from the Atlas officeholders v3 export (2026-07-04).