Tablet 45: the courtyard gate checks the key, not the shape of the header

/courtyard/* and /chatzer/* admitted any `Authorization: Bearer <x>`.
Every test sent `Bearer test-token`; none sent a wrong one. Every
admitted request spends the day's manna.

VavPipeline.BigdeiKodesh.Gate: keys are a file (Construction §4.6 —
never env, never config, never git), one `tier key` per line, tiers
courtyard < chatzer (the inner ring opens the outer). Constant-time
compare against every line; no file / empty / unreadable → nobody
passes, GATE_NO_KEYS in the log, the caller told only "missing or
invalid". 403 FORBIDDEN for an outer key at an inner gate. Read on
every request so a rotated key is live in ~1 min without a rollout.

Deploy: Secret shorashim-api-keys projected at
/etc/shorashim/secrets/api_keys (vav-pipeline only, 0440),
API_KEYS_FILE in the configmap, template + issue/rotate recipe in
secrets.yaml and KOHEN.md "Issuing a key". Spec: tamid §1.1 (gate,
403), vayakhel §4.6. Doorpost 91d09d8d… → 42b38626….
Tests: tablet45_gate_test (parse, tiers, wrong/near/empty/no key, no
file) — Elixir 527/0.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

vav_pipeline/config/test.exs

@@ -6,6 +6,7 @@ config :logger, level: :warning
 config :vav_pipeline,
   l1_mount_point: "../l1",
   manna_provision_file: "test/fixtures/manna/today.json",
+  api_keys_file: "test/fixtures/api_keys",
   cycle_boundary_check_interval_ms: :timer.hours(24),
   http_port: 0