feat(sql): add gov_population_yearly view

Exposes one row per (year, canonical_govid) drawn from long.population.
Used by per-capita denominators and peer matching.

inst/sql/32-gov_population_yearly.sql

@@ -0,0 +1,8 @@
+CREATE OR REPLACE VIEW gov_population_yearly AS
+SELECT DISTINCT
+  year,
+  canonical_govid,
+  population,
+  popyear
+FROM long
+WHERE population IS NOT NULL;