fix: separate Anthropic OAuth tokens from API keys

Persist OAuth/setup tokens in ANTHROPIC_TOKEN instead of ANTHROPIC_API_KEY.
Reserve ANTHROPIC_API_KEY for regular Console API keys.

Changes:
- anthropic_adapter: reorder resolve_anthropic_token() priority —
  ANTHROPIC_TOKEN first, ANTHROPIC_API_KEY as legacy fallback
- config: add save_anthropic_oauth_token() / save_anthropic_api_key() helpers
  that clear the opposing slot to prevent priority conflicts
- config: show_config() prefers ANTHROPIC_TOKEN for display
- setup: OAuth login and pasted setup-tokens write to ANTHROPIC_TOKEN
- setup: API key entry writes to ANTHROPIC_API_KEY and clears ANTHROPIC_TOKEN
- main: same fixes in _run_anthropic_oauth_flow() and _model_flow_anthropic()
- main: _has_any_provider_configured() checks ANTHROPIC_TOKEN
- doctor: use _is_oauth_token() for correct auth method validation
- runtime_provider: updated error message
- run_agent: simplified client init to use resolve_anthropic_token()
- run_agent: updated 401 troubleshooting messages
- status: prefer ANTHROPIC_TOKEN in status display
- tests: updated priority test, added persistence helper tests

Cherry-picked from PR #1141 by kshitijk4poor, rebased onto current main
with unrelated changes (web_policy config, blocklist CLI) removed.

Co-authored-by: kshitijk4poor <kshitijk4poor@users.noreply.github.com>

hermes_cli/runtime_provider.py

@@ -159,7 +159,7 @@ def resolve_runtime_provider(
         token = resolve_anthropic_token()
         if not token:
             raise AuthError(
-                "No Anthropic credentials found. Set ANTHROPIC_API_KEY, "
+                "No Anthropic credentials found. Set ANTHROPIC_TOKEN or ANTHROPIC_API_KEY, "
                 "run 'claude setup-token', or authenticate with 'claude /login'."
             )
         return {