feat!: require corpus schema_version 4 (Phase P canonical ids)

BREAKING CHANGE: canonical_govid is now uniformly 12 characters across
every vintage; corpora built against schema_version 3 are rejected.
Bumps MinCorpusSchema/MaxCorpusSchema to 4 and expected_version in
cog_open(). canonical_fips_xwalk grows to the 14-column Phase P master
schema (adds legacy_govs_id, census_geoid, id_source; confidence is
renamed to pop_confidence); .empty_xwalk_tibble() is rewritten to match.

R/search.R

@@ -126,9 +126,10 @@ cog_gov_search <- function(name = NULL, state = NULL, type = NULL) {
     canonical_govid = character(0), gov_name = character(0),
     govs_type = integer(0), type_label = character(0),
     fips_state = character(0), fips_county = character(0),
-    fips_place = character(0), first_year = integer(0),
-    last_year = integer(0), population_acs = integer(0),
-    confidence = character(0)
+    fips_place = character(0), legacy_govs_id = character(0),
+    first_year = integer(0), last_year = integer(0),
+    census_geoid = character(0), population_acs = integer(0),
+    pop_confidence = character(0), id_source = character(0)
   )
 }
 

R/session.R

@@ -12,7 +12,7 @@ cog_open <- function(url = .resolve_url(),
   DBI::dbExecute(con, "INSTALL httpfs; LOAD httpfs;")
 
   manifest <- .fetch_or_cache_manifest(url, cache_dir)
-  .validate_schema(manifest, expected_version = 3L)
+  .validate_schema(manifest, expected_version = 4L)
   .validate_scope(manifest)
 
   .register_views(con, url, manifest)