feat: basis= harmonized/raw with v4/v5 dual-accept

Adds schema_version 5 support alongside the existing v4 corpus:
.validate_schema() now accepts a supported set (4, 5) instead of a single
expected version, and cog_spending()/cog_revenue() gain basis =
c("harmonized", "raw"). Harmonized basis routes to new
spending_annotated_harmonized / revenue_annotated_harmonized views built on
spending_long_harmonized / revenue_long_harmonized (REPLACE(harmonized_code
AS item_code), excluding aggregate and NA-harmonized rows); raw basis is
byte-identical to the pre-Phase-R2 behavior. On a v4 corpus, an unspecified
basis silently resolves to "raw" with a provenance note; an explicit
basis = "harmonized" aborts with an actionable message.

Provenance gains basis, basis_note, and a harmonization block
(applied/na_rows_excluded/na_amount_excluded). The five new schema-v5-only
SQL views (harmonized long/annotated views, harmonization_map,
harmonization_recipes, series_breaks_pq) are registered conditionally on
manifest$schema_version >= 5, since DuckDB's read_parquet() errors eagerly
at CREATE VIEW time when the backing file doesn't exist on a v4 corpus.

Fixture corpus regenerated to schema_version 5 / years 2011, 2012, 2019,
2020 (2011->2012 spans the wide-aggregate -> modern-leaf format boundary
needed for the harmonization/recipe work), with the harmonization_map /
harmonization_recipes / series_breaks parquet tables bundled alongside the
existing metadata registries.

R/provenance.R

@@ -4,7 +4,9 @@
 #' @noRd
 .build_provenance <- function(verb, call, govid, years, category,
                               per_capita, adjust_to_year, result, sql,
-                              subtype_col) {
+                              subtype_col, basis = NA_character_,
+                              basis_note = NA_character_,
+                              harmonization = NULL) {
   manifest <- .uscogdata_env$manifest
 
   codes <- result[["codes_included"]]
@@ -38,6 +40,12 @@
     ),
     years = as.integer(years),
     category = category,
+    basis = basis,
+    basis_note = basis_note,
+    harmonization = harmonization %||% list(
+      applied = FALSE, na_rows_excluded = 0L, na_amount_excluded = 0,
+      note = NA_character_
+    ),
     scope = list(
       gov_types_included = as.integer(unlist(manifest$scope$gov_types_included)),
       gov_types_excluded = as.integer(unlist(manifest$scope$gov_types_excluded)),