feat(minimax-oauth): full integration with peer OAuth providers

Close integration gaps discovered by auditing qwen-oauth's file coverage.
These are surfaces the original salvage missed — they all existed on
main and were added in the 747 commits since PR #15203 was opened.

Coverage added:
- agent/credential_pool.py: seed pool from auth.json providers.minimax-oauth
  so `hermes auth list` reflects logged-in state and
  `hermes auth remove minimax-oauth <N>` works through the standard flow.
- agent/credential_sources.py: register RemovalStep for minimax-oauth
  with suppression-aware `_clear_auth_store_provider`.
- agent/models_dev.py: PROVIDER_TO_MODELS_DEV mapping (-> 'minimax' family).
- hermes_cli/providers.py: HermesOverlay entry (anthropic_messages transport,
  oauth_external auth_type, api.minimax.io/anthropic base).
- hermes_cli/model_normalize.py: add to _MATCHING_PREFIX_STRIP_PROVIDERS so
  `minimax-oauth/MiniMax-M2.7` in config.yaml gets correctly repaired.
- hermes_cli/status.py: render MiniMax OAuth block in `hermes doctor`
  (logged-in / region / expires_at / error).
- hermes_cli/web_server.py: register in OAUTH_PROVIDER_REGISTRY + dispatch
  branch in _resolve_provider_status so the dashboard auth page shows it.
- website/docs/integrations/providers.md: full 'MiniMax (OAuth)' section.
- website/docs/reference/cli-commands.md: --provider enum.
- website/docs/user-guide/features/fallback-providers.md: fallback table row.
- scripts/release.py AUTHOR_MAP: amanning3390 mapping (CI gate).

agent/credential_sources.py

@@ -252,6 +252,19 @@ def _remove_nous_device_code(provider: str, removed) -> RemovalResult:
     return result
 
 
+def _remove_minimax_oauth(provider: str, removed) -> RemovalResult:
+    """MiniMax OAuth lives in auth.json providers.minimax-oauth — clear it.
+
+    Same pattern as Nous: single-source OAuth state with refresh tokens.
+    Suppression of the `oauth` source ensures the pool reseed path
+    (_seed_from_singletons) doesn't instantly undo the removal.
+    """
+    result = RemovalResult()
+    if _clear_auth_store_provider(provider):
+        result.cleaned.append(f"Cleared {provider} OAuth tokens from auth store")
+    return result
+
+
 def _remove_codex_device_code(provider: str, removed) -> RemovalResult:
     """Codex tokens live in TWO places: our auth store AND ~/.codex/auth.json.
 
@@ -389,6 +402,11 @@ def _register_all_sources() -> None:
         remove_fn=_remove_qwen_cli,
         description="~/.qwen/oauth_creds.json",
     ))
+    register(RemovalStep(
+        provider="minimax-oauth", source_id="oauth",
+        remove_fn=_remove_minimax_oauth,
+        description="auth.json providers.minimax-oauth",
+    ))
     register(RemovalStep(
         provider="*", source_id="config:",
         match_fn=lambda src: src.startswith("config:") or src == "model_config",