docs: update specs and architecture docs with usp_/fn_ naming convention

openspec/specs/search-processing/spec.md

@@ -545,7 +545,7 @@ The system SHALL optionally extract Manufacturing Information System (MIS) data
 
 - `ExtractMisData` flag from search criteria
 - `ItemOperationMisFilter` entries (when filtering by specific MIS)
-- Work order step data joined with MIS matching function `dbo.MatchMIS`
+- Work order step data joined with MIS matching function `dbo.fn_MatchMIS`
 
 #### Outputs
 
@@ -562,7 +562,7 @@ The system SHALL optionally extract Manufacturing Information System (MIS) data
 #### Business Rules
 
 - MIS extraction is only performed when `ExtractMisData = true`
-- The `MatchMIS` table-valued function handles MIS record matching logic
+- The `fn_MatchMIS` table-valued function handles MIS record matching logic
 - RoutingMatch indicates match to F3112Z1 (work order routing) records
 - MasterMatch indicates match to F3003 (item master routing) records
 - Non-match results include work orders where neither RoutingMatch nor MasterMatch is true, or MisNumber is null
@@ -792,9 +792,9 @@ Circular references in work order relationships are **handled implicitly** by th
 
 MIS non-match results are **always included** when `ExtractMisData = true`. The non-match data is valuable for quality investigations and should not be optional.
 
-### Decision: MatchMIS function availability
+### Decision: fn_MatchMIS function availability
 
-The `dbo.MatchMIS` table-valued function **must be recreated** in the migrated database. It is a custom SQL Server function that implements MIS record matching logic based on work order routing, master routing, and operation parameters.
+The `dbo.fn_MatchMIS` table-valued function **must be recreated** in the migrated database. It is a custom SQL Server function that implements MIS record matching logic based on work order routing, master routing, and operation parameters.
 
 ### Decision: Filter validation location