feat(egress): first-class x-api-key providers + hot reload via management API

Both wired against features the iron-proxy author (@mslipper) confirmed on
PR #30179 — and both verified present in the pinned v0.39.0 source.

Header-auth providers (match_headers):
- New _HEADER_AUTH_PROVIDERS: Anthropic native (x-api-key), Azure OpenAI
  (api-key on *.openai.azure.com / *.cognitiveservices / *.services.ai),
  Gemini (x-goog-api-key + ?key= query param via match_query).
- TokenMapping grows match_headers + alias_env_names; per-provider header
  sets flow into the secrets rules; mappings.json roundtrips them
  (legacy files load with the Authorization default).
- GEMINI_API_KEY / GOOGLE_API_KEY collapse into ONE mapping (two
  require-rules on the same host would reject each other); the sandbox
  gets the token under both names, and the proxy child env mirrors the
  alias into the canonical name when only the alias is set.
- Docker backend injects alias env names alongside canonical ones.
- The fail-closed tier is now empty, so fail_on_uncovered_providers and
  discover_blocked_providers are deleted (dead toggle otherwise);
  _NON_BEARER_PROVIDERS shrinks to genuinely-unswappable signature auth
  (AWS SigV4, GCP service-account OAuth) — warn-only, as before.

Management API (hot reload):
- Generated proxy.yaml enables the v0.39 management listener: loopback
  only at tunnel_port+2, bearer key from HERMES_IRON_PROXY_MGMT_KEY.
- Key minted at setup (management.token, 0600); start_proxy injects it
  (v0.39 refuses to start when api_key_env is empty).
- hermes egress reload -> POST /v1/reload: re-reads proxy.yaml and
  atomically swaps the pipeline; 422 leaves the running ruleset
  untouched; actionable errors for not-running / pre-management config /
  key mismatch. Secrets changes still require restart (daemon env is
  read at spawn) — the CLI says so.

Validation: 218/218 unit+CLI+docker tests; 3/3 gated live E2E against the
real v0.39.0 binary (Authorization swap, x-api-key swap, live reload with
token rotation on the same pid). Docs updated.

tools/environments/docker.py

@@ -497,10 +497,15 @@ def _egress_proxy_args_for_docker() -> tuple[list[str], dict[str, str], list[str
 
     # Surface the per-provider proxy tokens under the standard provider env
     # names so existing SDKs and provider clients work unchanged inside the
-    # sandbox.  Keep the HERMES_PROXY_TOKEN_* aliases for diagnostics.
+    # sandbox.  Alias env names (e.g. GOOGLE_API_KEY for GEMINI_API_KEY)
+    # receive the same token so SDKs reading either name authenticate
+    # through the proxy.  Keep the HERMES_PROXY_TOKEN_* aliases for
+    # diagnostics.
     for m in mappings:
         env_overrides[m.real_env_name] = m.proxy_token
         env_overrides[f"HERMES_PROXY_TOKEN_{m.real_env_name}"] = m.proxy_token
+        for alias in getattr(m, "alias_env_names", ()) or ():
+            env_overrides[alias] = m.proxy_token
 
     # On Linux, host.docker.internal isn't populated by default — Docker Desktop
     # adds it on macOS/Windows; on Linux we need an explicit --add-host with