feat(providers): add PPQ (PayPerQ) as aggregator provider

Add PPQ (PayPerQ) as a first-class provider with aggregator support,
following the same pattern as OpenRouter.

- ProviderConfig in auth.py with PPQ_API_KEY / PPQ_BASE_URL env vars
- HermesOverlay in providers.py with is_aggregator=True
- Dynamic model fetching via /v1/models (no static model list)
- Aliases: payperq, ppq.ai -> ppq
- Label override: PPQ (PayPerQ)
- Full test coverage: registry, aliases, labels, live catalog, fallback

hermes_cli/providers.py

@@ -90,6 +90,13 @@ HERMES_OVERLAYS: Dict[str, HermesOverlay] = {
         extra_env_vars=("GLM_API_KEY", "ZAI_API_KEY", "Z_AI_API_KEY"),
         base_url_env_var="GLM_BASE_URL",
     ),
+    "ppq": HermesOverlay(
+        transport="openai_chat",
+        is_aggregator=True,
+        extra_env_vars=("PPQ_API_KEY",),
+        base_url_override="https://api.ppq.ai",
+        base_url_env_var="PPQ_BASE_URL",
+    ),
     "kimi-for-coding": HermesOverlay(
         transport="openai_chat",
         base_url_env_var="KIMI_BASE_URL",
@@ -203,6 +210,10 @@ ALIASES: Dict[str, str] = {
     "z.ai": "zai",
     "zhipu": "zai",
 
+    # ppq
+    "payperq": "ppq",
+    "ppq.ai": "ppq",
+
     # xai
     "x-ai": "xai",
     "x.ai": "xai",
@@ -313,6 +324,7 @@ _LABEL_OVERRIDES: Dict[str, str] = {
     "copilot-acp": "GitHub Copilot ACP",
     "stepfun": "StepFun Step Plan",
     "xiaomi": "Xiaomi MiMo",
+    "ppq": "PPQ (PayPerQ)",
     "local": "Local endpoint",
     "bedrock": "AWS Bedrock",
     "ollama-cloud": "Ollama Cloud",