feat(kenari): add new provider

[doedja]

What

Adds Kenari, an Indonesian LLM gateway with an OpenAI-compatible API, as a provider.

• internal/providers/configs/kenari.json: 31 chat models (all support tool calling and streaming), generated from the live catalog at GET https://kenari.id/v1/models (public, no auth)
• Registered in internal/providers/providers.go (alphabetical slot)

Details

• type: openai-compat, endpoint https://kenari.id/v1, key env $KENARI_API_KEY
• Costs are set to 0 like copilot and kimi-coding: Kenari bills a local-currency (IDR) wallet per token, so there is no stable USD per-token price to pin. Live pricing is on the models endpoint and https://kenari.id/models
• context_window, can_reason, reasoning_levels, and supports_attachments come from the same models endpoint
• Free-tier model variants (:free ids) are excluded, only the stable paid catalog is listed
• Defaults: claude-sonnet-5 (large) / deepseek-v4-flash (small)

Testing

• go build ./... and go test ./... pass (41 tests, 22 packages)
• gofmt clean

Docs: https://kenari.id/docs

[doedja]

Rebased onto current main, and this now ships an updater at cmd/kenari/main.go, registered in .github/workflows/update.yml and the Taskfile, so the model data refreshes on the same schedule as the other providers instead of needing hand maintenance. That was the piece the original version was missing.

Verified locally before pushing: go build ./... and go test -count=1 both clean, and running the updater reproduces the committed internal/providers/configs/kenari.json byte for byte, with a second run producing no change.

Costs are 0 on every entry. The gateway bills a prepaid wallet in Indonesian rupiah, so a USD per-token figure would be invented and would drift with the exchange rate.