feat(coderd): support multi-value status, owner, and template workspace filters - #27909

🤖 This PR was written by Coder Agents on behalf of Jake Howell.

Resolves DEVEX-424.

Problem

When the frontend sends multiple chips for the same filter key (e.g. status:running status:stopped), Go's URL parser produces {"status": ["running", "stopped"]} but parser.String silently keeps only the first value. The Workspaces list endpoint therefore drops the extra values, making multi-select filters appear broken even though the client serializes correctly.

Changes

The status, owner, and template filters on the Workspaces list endpoint now accept multiple values.

• coderd/database/queries/workspaces.sql
  • status: the single-value @status :: text CASE becomes an @statuses :: text[] membership check. Each requested status is OR'd using the existing transition/job-status mapping. The raw job-status fallback excludes the running/succeeded job statuses so single-value semantics are preserved (e.g. running still means succeeded+start, not an in-progress build).
  • owner: @owner_username :: text becomes @owner_usernames :: text[] via owner_id = ANY(SELECT id FROM users WHERE lower(username) = ANY(@owner_usernames) AND deleted = false).
  • template: @template_name :: text becomes @template_names :: text[] via template_id = ANY(SELECT id FROM templates WHERE lower(name) = ANY(@template_names) AND deleted = false).
• coderd/searchquery/search.go: status parses with ParseCustomList(..., ParseEnum[WorkspaceStatus]) (keeps per-value validation); owner/template use parser.Strings. Repeated keys and CSV both work.
• coderd/workspaces.go: the owner:me shortcut now resolves any me entry to the requesting user's username so it composes with other owners via ANY(...).
• coderd/database/modelqueries.go: wrap the three params with pq.Array(...) in GetAuthorizedWorkspaces.
• Regenerated queries.sql.go via make gen. GetWorkspacesParams fields become Statuses []string, OwnerUsernames []string, TemplateNames []string (WorkspaceStatus is a Go string type, not a Postgres enum, so sqlc emits []string).

Scope note (backend only)

The ticket's Definition of Done includes a frontend multiSelect: true flip in WorkspacesPageView.tsx. That change depends on FilterSearchField, introduced by the blocker DEVEX-422, which is not yet on main (no component, no category definitions). This PR delivers the backend half named in the ticket title / need-backend label; the one-line frontend flip lands once DEVEX-422 merges.

dbmem was removed from the codebase (#18803), so the ticket's dbmem.go step no longer applies. Filter tests run against real Postgres.

Testing

• coderd/searchquery/search_test.go: migrated expected values to slices; added multi-value owner/template/status cases (repeated keys + CSV) and an invalid-status case; normalized nil vs empty slices.
• coderd/workspaces_test.go: added end-to-end MultipleStatuses, MultipleOwners, MultipleTemplates subtests (frontend → API → correct results), and kept single-value assertions to confirm no breaking change.
• make gen, make fmt, golangci-lint, and the full pre-commit suite pass.