feat: view registration from inst/sql/

Seven DuckDB views register on session open: long (raw), spending_long
and revenue_long (prefix-filtered, NOT is_aggregate per reader-spec §4),
canonical_fips_xwalk and summary_categories (identity), spending_annotated
and revenue_annotated (LEFT JOIN xwalk + categories for verb composition).

File prefix `NN-` enforces creation order so *_annotated views resolve
their *_long dependencies.

Deviation from plan: series_breaks/cpi_annual/legacy_aggregate_map and
*_with_transforms views are deferred — their backing parquets are not
in the v0.1 corpus (manifest.files.metadata only lists canonical_fips_xwalk
and summary_categories). The verbs will compute CPI adjustment verb-side
against a bundled cpi table in a later task.

inst/sql/40-spending_annotated.sql

@@ -0,0 +1,16 @@
+CREATE OR REPLACE VIEW spending_annotated AS
+SELECT
+  s.*,
+  x.gov_name       AS xwalk_gov_name,
+  x.govs_type,
+  x.type_label,
+  x.fips_state     AS xwalk_fips_state,
+  x.fips_county    AS xwalk_fips_county,
+  x.fips_place,
+  x.population_acs,
+  c.category,
+  c.category_type,
+  c.spend_subtype
+FROM spending_long s
+LEFT JOIN canonical_fips_xwalk x USING (canonical_govid)
+LEFT JOIN summary_categories   c USING (item_code);