feat(deeplink): allow overriding OpenCode npm package via URL param

[oaker-io]

Summary

• Adds an npm parameter to the ccswitch:// provider deeplink so callers can pick which @ai-sdk/* package the OpenCode provider should use.
• Fixes the case where a relay exposes both OpenAI-compatible and Gemini-native endpoints: today a Gemini import lands as @ai-sdk/openai-compatible, and the user has to open the provider config and hand-edit npm to @ai-sdk/google before chat works.
• Default stays @ai-sdk/openai-compatible, so existing deeplinks are unaffected.

What changed

• DeepLinkImportRequest gains npm: Option<String> (camelCase npm in the URL).
• parse_deeplink_url reads npm from the query string for the provider resource.
• merge_additive_config (OpenCode / OpenClaw JSON config pass-through) now carries npm from the Base64 config when the URL param is absent.
• build_opencode_settings uses the override and falls back to @ai-sdk/openai-compatible.
• Docs: all three locales of 5.3-deeplink.md get a new row for npm.

Context

Example deeplink from a relay that routes Gemini under /v1beta:

ccswitch://v1/import?resource=provider&app=opencode&name=Relay
  &endpoint=https%3A%2F%2Frelay.example.com%2Fv1beta
  &apiKey=sk-...
  &model=gemini-3-flash
  &npm=%40ai-sdk%2Fgoogle

Without this change the imported provider is usable for discovery but fails on the first chat because the openai-compatible SDK can't speak Gemini-native. With the change, one click lands a working config.

Tests

• test_parse_opencode_deeplink_with_npm_param — URL param survives parsing.
• test_build_opencode_provider_defaults_npm_when_absent — default unchanged.
• test_build_opencode_provider_honors_npm_override — override wins.

All 24 deeplink::tests::* pass locally (cargo test deeplink). cargo fmt --check and cargo clippy -- -D warnings clean.

Test plan

• cargo fmt --check passes
• cargo clippy --manifest-path src-tauri/Cargo.toml -- -D warnings passes
• cargo test --manifest-path src-tauri/Cargo.toml passes (24 deeplink tests + 2 integration tests)
• Manual: trigger an OpenCode deeplink with npm=@ai-sdk/google and confirm the provider config in CC Switch shows the overridden package

🤖 Generated with Claude Code

[farion1231]

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[chatgpt-codex-connector]

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