Fix Windows plugin loader interop for opencode 1.3.17

[bhaktatejas922]

Summary

• avoid MorphSDK's aggregate root ESM entrypoint in the plugin runtime load path
• use the edge SDK entry for fast apply/compact and the WarpGrep client-only entry for search
• pass a plugin-local WarpGrep provider so local search avoids the SDK LocalRipgrepProvider import that statically named-imports CJS @vscode/ripgrep
• add a focused loader-compatibility regression test guarding these entrypoints

Closes #10.

Tests

• bun test
• bun run typecheck
• bun run build
• bun -e "const m = await import('./dist/index.js'); if (typeof m.default !== 'function') throw new Error('default export is not a function'); console.log('ok')"
• rg -n "from "@morphllm/morphsdk"|import \{ rgPath \}|@vercel/oidc|getVercelOidcToken|LocalRipgrepProvider" dist/index.js index.ts (no matches)
• HOME=$tmp_home XDG_CONFIG_HOME=$tmp_home/.config npx -y opencode-ai@1.3.17 debug config --print-logs --log-level DEBUG (temporary config, local plugin path)
• bun run ci