#5469: docs: add Portkey AI gateway integration

## Summary Add documentation for integrating OpenClaw with [Portkey](https://portkey.ai), an AI gateway that provides observability, governance, cost tracking, and reliability features. - Add dedicated Portkey provider doc with quick start, config examples, and troubleshooting - Add Portkey mentions where relevant - Tested and verified working with `@openai/gpt-5.2` and `@anthropic/claude-sonnet-4-5` ## Changes - **New:** `docs/providers/portkey.md` - Full integration guide - **Updated:** `docs/providers/index.md` - Added Portkey to provider list - **Updated:** `docs/concepts/model-providers.md` - Added Portkey section with config example - **Updated:** `docs/gateway/local-models.md` - Added Portkey as proxy/gateway option - **Updated:** `docs/gateway/configuration.md` - Added Portkey to custom providers list - **Updated:** `docs/testing.md` - Added Portkey to the custom endpoints list ## Key features documented - Unified OpenAI-compatible API (`api: "openai-completions"` works for all providers, including Anthropic) - Model ID format: `@provider/model` (e.g., `@anthropic/claude-sonnet-4-5`, `@openai/gpt-5.2`) - Portkey Configs for fallbacks, load balancing, caching, and retries - Tracing with `x-portkey-trace-id` header - Budget controls and rate limits ## Test plan - [x] Verified OpenAI model via Portkey: `@openai/gpt-5.2` - [x] Verified Anthropic model via Portkey: `@anthropic/claude-sonnet-4-5` <!-- greptile_comment --> <h2>Greptile Overview</h2> <h3>Greptile Summary</h3> This PR adds a new Portkey provider documentation page and references Portkey across existing docs where OpenAI-compatible proxies/gateways and custom `models.providers` are discussed. Changes are limited to documentation: adding `docs/providers/portkey.md` (quick start, configuration examples, tracing/budget tips, troubleshooting) and updating provider indexes and gateway/model-provider docs to mention Portkey as an option. <h3>Confidence Score: 4/5</h3> - This PR is safe to merge; changes are documentation-only with a couple of wording/clarity nits to address. - No runtime code changes. The main risks are user confusion from categorizing Portkey as a local proxy and a small typo/formatting issues in docs. - docs/providers/portkey.md; docs/gateway/local-models.md; docs/providers/index.md <!-- greptile_other_comments_section --> _{(2/5) Greptile learns from your feedback when you react with thumbs up/down!} <!-- /greptile_comment -->