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/ma/counties/bristol/index.md

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

data/jurisdictions/us/states/ma/counties/bristol/municipalities/fall-river/people/paul-coogan.md

@@ -0,0 +1,39 @@
+---
+type: Person
+title: "Paul Coogan"
+description: "Mayor, Fall River, MA"
+role: "Mayor, Fall River, MA"
+level: "municipal"
+branch: "executive"
+state: "MA"
+tenure:
+  start: "2026-06-20"
+  current: true
+ids:
+  person: "a8c15259-f099-4e1e-a1a8-283760b87b30"
+  office: "c4950ff7-03a7-497d-ae96-1c087fc3dd40"
+  tenure: "c4248543-6c79-40b0-8d24-76994d029c25"
+  jurisdiction: "98fb4134-ffce-496a-afdd-06eaf16b4b40"
+sources:
+  - field: office
+    source: "Wikidata"
+  - field: tenure
+    source: "Wikidata"
+  - field: jurisdiction
+    source: "Census TIGER 2024"
+confidence: official
+tags: [officeholder, municipal, executive, ma]
+timestamp: "2026-07-04"
+---
+
+# Paul Coogan
+
+Current Mayor, Fall River, MA.
+
+## Sources
+
+- office: Wikidata
+- tenure: Wikidata
+- jurisdiction: Census TIGER 2024
+
+Generated from the Atlas officeholders v3 export (2026-07-04).

data/jurisdictions/us/states/ma/counties/bristol/municipalities/new-bedford/people/jonathan-f-mitchell.md

@@ -0,0 +1,39 @@
+---
+type: Person
+title: "Jonathan F. Mitchell"
+description: "Mayor, New Bedford, MA"
+role: "Mayor, New Bedford, MA"
+level: "municipal"
+branch: "executive"
+state: "MA"
+tenure:
+  start: "2026-06-20"
+  current: true
+ids:
+  person: "4a2b4441-2517-4b50-99e7-d5e7d47100f1"
+  office: "715aa7f9-e82b-405b-bbc7-a74d0c884101"
+  tenure: "6c1e7ec7-015e-436c-b69a-5dfdc97b17e8"
+  jurisdiction: "0c01ef6a-3c18-40ee-b76e-714099f94030"
+sources:
+  - field: office
+    source: "Wikidata"
+  - field: tenure
+    source: "Wikidata"
+  - field: jurisdiction
+    source: "Census TIGER 2024"
+confidence: official
+tags: [officeholder, municipal, executive, ma]
+timestamp: "2026-07-04"
+---
+
+# Jonathan F. Mitchell
+
+Current Mayor, New Bedford, MA.
+
+## Sources
+
+- office: Wikidata
+- tenure: Wikidata
+- jurisdiction: Census TIGER 2024
+
+Generated from the Atlas officeholders v3 export (2026-07-04).

data/jurisdictions/us/states/ma/counties/bristol/municipalities/taunton/people/shaunna-o-connell.md

@@ -0,0 +1,39 @@
+---
+type: Person
+title: "Shaunna O'Connell"
+description: "Mayor, Taunton, MA"
+role: "Mayor, Taunton, MA"
+level: "municipal"
+branch: "executive"
+state: "MA"
+tenure:
+  start: "2026-06-20"
+  current: true
+ids:
+  person: "ef0e3045-8edd-4a31-a2af-c43df96453c6"
+  office: "ec2fe6e9-0321-41d3-aa0b-76990da5d639"
+  tenure: "3d0fe398-260d-4bb6-bb66-27d1187fb226"
+  jurisdiction: "306939c1-f549-4768-9346-ccc9741a2790"
+sources:
+  - field: office
+    source: "Wikidata"
+  - field: tenure
+    source: "Wikidata"
+  - field: jurisdiction
+    source: "Census TIGER 2024"
+confidence: official
+tags: [officeholder, municipal, executive, ma]
+timestamp: "2026-07-04"
+---
+
+# Shaunna O'Connell
+
+Current Mayor, Taunton, MA.
+
+## Sources
+
+- office: Wikidata
+- tenure: Wikidata
+- jurisdiction: Census TIGER 2024
+
+Generated from the Atlas officeholders v3 export (2026-07-04).