OpenViking 0.3.x requires X-OpenViking-Account and X-OpenViking-User headers for ROOT API key requests to tenant-scoped APIs. Previously the `!="default"` guard skipped these headers when account/user were the literal string "default", causing INVALID_ARGUMENT errors.
Remove the `!="default"` guard so headers are sent whenever account/user are truthy. Empty strings are still correctly skipped since `""` is falsy.
Update tests to reflect the new behavior:
- test_viking_client_headers_send_tenant_when_default: asserts "default" headers ARE present
- test_viking_client_headers_send_tenant_when_empty_falls_back_to_default: asserts "default" headers ARE present from constructor fallback
Based on #21775 by @happy5318
Authenticated remote OpenViking servers derive tenancy from the Bearer
key, but the client was always sending X-OpenViking-Account and
X-OpenViking-User — defaulted to the literal string "default" — which
overrode the key-derived tenant and broke auth.
- _headers(): skip X-OpenViking-Account/-User when blank or "default"
(treats the legacy default value as unset, so existing installs don't
need to touch their .env)
- _headers(): send Authorization: Bearer <key> alongside X-API-Key for
standard HTTP auth compatibility
- health(): include auth headers so /health works against servers that
require authentication
Tests cover bearer emission, legacy "default" suppression, empty
suppression, real tenant passthrough, and authenticated health checks.
Fixes the same user report as #20695 (from @ZaynJarvis); that PR could
not be merged because its branch was stale against main and would have
reverted recent OpenViking work (#15696, local resource uploads, summary
URI normalization, fs-stat pre-check).
