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/nh/counties/merrimack/index.md

@@ -32,7 +32,7 @@ timestamp: "2026-07-03"
 
 # Merrimack County, NH
 
-County jurisdiction.
+County jurisdiction — 2 officeholders mapped.
 
 ## Demographics (ACS 2023)
 

data/jurisdictions/us/states/nh/counties/merrimack/municipalities/concord/people/byron-o-champlin.md

@@ -0,0 +1,39 @@
+---
+type: Person
+title: "Byron O. Champlin"
+description: "Mayor, Concord, NH"
+role: "Mayor, Concord, NH"
+level: "municipal"
+branch: "executive"
+state: "NH"
+tenure:
+  start: "2026-06-20"
+  current: true
+ids:
+  person: "0250bb9a-5204-4777-9db8-5967218c9256"
+  office: "7b9f549f-f31a-4ff9-9826-de3ff6fad1f8"
+  tenure: "4feb945e-5e45-4657-bdc6-4abf8cfd5a52"
+  jurisdiction: "204333d7-494c-4144-924f-64f932dac772"
+sources:
+  - field: office
+    source: "Wikidata"
+  - field: tenure
+    source: "Wikidata"
+  - field: jurisdiction
+    source: "Census TIGER 2024"
+confidence: official
+tags: [officeholder, municipal, executive, nh]
+timestamp: "2026-07-04"
+---
+
+# Byron O. Champlin
+
+Current Mayor, Concord, NH.
+
+## Sources
+
+- office: Wikidata
+- tenure: Wikidata
+- jurisdiction: Census TIGER 2024
+
+Generated from the Atlas officeholders v3 export (2026-07-04).

data/jurisdictions/us/states/nh/counties/merrimack/municipalities/franklin/people/desiree-mclaughlin.md

@@ -0,0 +1,39 @@
+---
+type: Person
+title: "Desiree McLaughlin"
+description: "Mayor, Franklin, NH"
+role: "Mayor, Franklin, NH"
+level: "municipal"
+branch: "executive"
+state: "NH"
+tenure:
+  start: "2026-06-20"
+  current: true
+ids:
+  person: "2d7bb27c-5ae2-44b1-8bb0-cdd2bd1b3f72"
+  office: "47b4bcf0-63f7-401b-8be6-1aefc085da1e"
+  tenure: "66574322-e8b3-4363-87e6-4ea36da2c434"
+  jurisdiction: "a868225a-5577-4c01-8e3c-a636f58d9b70"
+sources:
+  - field: office
+    source: "Wikidata"
+  - field: tenure
+    source: "Wikidata"
+  - field: jurisdiction
+    source: "Census TIGER 2024"
+confidence: official
+tags: [officeholder, municipal, executive, nh]
+timestamp: "2026-07-04"
+---
+
+# Desiree McLaughlin
+
+Current Mayor, Franklin, NH.
+
+## Sources
+
+- office: Wikidata
+- tenure: Wikidata
+- jurisdiction: Census TIGER 2024
+
+Generated from the Atlas officeholders v3 export (2026-07-04).