#2560 extensions: cold-path catalog rebuild skips sources whose type is not a string literal, dropping them for one process lifetime

Summary

When the extension catalog is rebuilt on startup (the cold path after an invalidation such as a source-dirs fingerprint change, or after deleting _extension_catalog.db), ExtensionLoader.populateCatalogFromDir indexes each source file with the static regex extractTypeFromSource only. Files whose export block does not contain a string-literal type: get no catalog row for that whole process — for example export const extension = withGcpVerbosity(extensionDefinition). It emits the warning "type field could not be extracted from the export block" and skips the file.

The next process start sees the catalog as populated, the stale-file scan finds the missing files, and rebundleAndUpdateCatalog imports the bundle and catalogs them with the real type. So the extension is missing for exactly one process lifetime. For a long-running swamp serve, that is the whole lifetime of the instance.

Reproduction (found while fixing swamp-club#2557)

1. With the released binary, pull @swamp/gcp-organization@2026.09.24.1 through swamp serve. Because of #2557, 7 extension files get no catalog row.
2. Start the #2557-fixed serve once. The pull changed the source-dirs fingerprint, so startup takes the cold path. The two files with a literal type: come back, but the five withGcpVerbosity(...) files (gcp_iam_bindings, gcp_iam_inventory, gcp_quota_inventory, gcp_org_policy_management, gcp_organisation_costs) stay missing, and inventory_iam is absent from @swamp/gcp/cloudresourcemanager/organizations.
3. Start it a second time: all 23 rows are present and the methods attach.

The same cold-path warning also fires for files that appear to have a literal type (gcp_hierarchy.ts, gcp_project_offboarding.ts), so swamp doctor extensions shows 20 noisy warnings for this package.

Expected

The cold path should catalog every extension source it can bundle, not only those whose type the regex can read. For example, when the regex fails, fall back to importing the bundle for the type, as the stale-file scan does. Consider startup cost, since the cold path runs with indexOnly to avoid imports.

Notes

• Code: src/domain/extensions/extension_loader.ts populateCatalogFromDir (the if (!extracted) { emitTypeExtractionFailure(...); continue; } branch).
• Recovery today: restart a second time, or run swamp doctor extensions --repair.
• Also seen during the #2557 repro, possibly related: on serve reload, extensions on sibling types (gcp_hierarchy, gcp_service_account_management, gcp_security_findings) log "method ... already exists" warnings, which suggests a second attach pass. The methods stay present.