feat: add OrcaRouter as a named provider template

[XiaoHuo888-hue]

Summary

This adds OrcaRouter as a named provider template in both the interactive TUI (provider add form) and the scriptable CLI (provider add --template orcarouter), wired the same way the existing DeepSeek preset is, so the template list, generated settings and tests stay consistent.

OrcaRouter is an OpenAI-compatible model routing gateway: one key (keys start with sk-orca-) unlocks 150+ models from OpenAI, Anthropic, Google, DeepSeek, Qwen, MiniMax and xAI behind a single https://api.orcarouter.ai/v1 endpoint. It also runs gateway-level, zero-trust security for AI agents on the same endpoint — screening every prompt/response and governing every tool call on a default-deny basis, with no application code changes.

I'm an engineer on the OrcaRouter team.

What's added

• CLI (src-tauri/src/cli/commands/provider_input.rs)
  • New ProviderAddTemplate::Orcarouter template available for claude and codex apps.
  • Claude preset writes ANTHROPIC_BASE_URL=https://api.orcarouter.ai/v1 (native Anthropic endpoint) with default model orcarouter/fusion.
  • Codex preset generates a config.toml with base_url=https://api.orcarouter.ai/v1, wire_api="responses" and a model catalog (orcarouter/fusion, orcarouter/fusion-flash, orcarouter/fusion-mini).
  • Category aggregator, website https://www.orcarouter.ai, brand icon + color.
• TUI (src-tauri/src/cli/tui/form/provider_templates.rs, tests.rs)
  • OrcaRouter entry in the Claude and Codex template lists, mirroring the DeepSeek wiring in the add-provider form (fields, catalog rows, wire API and model defaults).
• Icons (src-tauri/src/provider_defaults.rs)
  • orcarouter entry in DEFAULT_PROVIDER_ICONS.

How to use

cc-switch provider add --template orcarouter
# or in the TUI:  Provider Add → template "OrcaRouter"

OrcaRouter is a named router — the virtual orcarouter/auto model picks an upstream per request (adaptive routing).

How tested

• cargo fmt --check clean.
• cargo test (provider template tests) pass, including new CLI + TUI tests for the OrcaRouter preset.
• Live-tested against the real API with a sk-orca- key:
  • POST https://api.orcarouter.ai/v1/messages (Anthropic format, model orcarouter/fusion) → 200
  • POST https://api.orcarouter.ai/v1/responses (OpenAI Responses format, model orcarouter/fusion) → 200
  • POST https://api.orcarouter.ai/v1/chat/completions (model orcarouter/fusion) → 200
  • GET https://api.orcarouter.ai/v1/models → 193 models (incl. orcarouter/auto, orcarouter/fusion, orcarouter/fusion-flash, orcarouter/fusion-mini)

Documentation impact

None — the preset is surfaced through the existing provider-add flows.