fix(ci): update 3 doc references to tooling/schema_version.py

asset-pipeline.md (2 locations) and systems-schema.sql still pointed
at import_economics.py as the SCHEMA_VERSION home after the extraction
to a shared module.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.claude/rules/asset-pipeline.md

@@ -52,7 +52,7 @@ CREATE TABLE meta (
 ```
 
 `schema_version` is a **monotonic semver string** (e.g. `"1.0.0"`), not a hash.
-It is defined as the `SCHEMA_VERSION` constant in `tooling/economy-db/import_economics.py`
+It is defined as the `SCHEMA_VERSION` constant in `tooling/schema_version.py`
 and must be bumped manually whenever the schema changes in a backwards-incompatible way.
 Unlike a SHA-1 hash, semver strings are orderable — this enables savegame migration
 lineage in Phase 5+: a save file can record which schema version it derives from and
@@ -183,6 +183,6 @@ loader can determine which migrations to apply by comparing that version to the
 current one.  `meta.schema_sha` retains the old SHA-1 for tamper detection.
 
 **When to bump `SCHEMA_VERSION`:** edit the `SCHEMA_VERSION = "1.0.0"` constant in
-`tooling/economy-db/import_economics.py` whenever a schema change is backwards-incompatible
+`tooling/schema_version.py` whenever a schema change is backwards-incompatible
 (column removed, type changed, FK constraint added, table dropped).  Additive changes
 (new nullable columns, new tables, new indexes) do not require a bump.