Fix Windows sqlite path check and Gemini embedding defaults

[buzuweidao]

Summary

This PR fixes two issues we hit while testing apps/memos-local-openclaw on Windows with Gemini:

1. Windows path handling for better-sqlite3

   • path.dirname(new URL(import.meta.url).pathname) produced /C:/... on Windows.
   • require.resolve() returned C:\..., so the plugin incorrectly concluded better-sqlite3 was outside the plugin directory and failed to load.
   • Switched to fileURLToPath(import.meta.url) and normalized both paths before comparison.

2. Gemini embedding defaults / compatibility

   • Default embedding model changed from text-embedding-004 to gemini-embedding-001.
   • Gemini embedding endpoint normalization now auto-corrects older v1/...:embedContent style values to the current v1beta/...:batchEmbedContents style.
   • README example model updated accordingly.

Validation

• Reproduced on Windows while installing and enabling the plugin under OpenClaw.
• Verified the TypeScript build succeeds locally with:
  • PUPPETEER_SKIP_DOWNLOAD=1 npm install
  • npm run build
• Verified Gemini embedding requests succeed against the official Gemini API when using gemini-embedding-001.

Notes

The published package we tested also exposed a Viewer-side Gemini test issue, but that code path does not appear in the current repo source tree under apps/memos-local-openclaw. This PR only includes the source changes I could trace and validate in the repository itself.

[syzsunshine219]

Thanks for the fix! Two separate improvements here:

1. Windows path fix (index.ts) — Duplicate of fix(memos-local-openclaw): normalize Windows paths when resolving better-sqlite3 #1265
   The fileURLToPath + path.normalize().toLowerCase() change is identical to what fix(memos-local-openclaw): normalize Windows paths when resolving better-sqlite3 #1265 already provides. Since fix(memos-local-openclaw): normalize Windows paths when resolving better-sqlite3 #1265 is a focused single-issue fix for the same problem (fix(windows): normalize plugin path when resolving better-sqlite3 to avoid false “outside plugin dir” #1192), we'll merge that one first. Please rebase this PR and drop the index.ts changes to avoid conflicts.
2. Gemini embedding defaults (gemini.ts + README.md) — Looks good ✅
   Updating the default model from text-embedding-004 to gemini-embedding-001 aligns with Google's latest recommendation.
   The normalizeGeminiEmbeddingEndpoint() helper correctly handles /v1/ → /v1beta/ and :embedContent → :batchEmbedContents misconfigurations.
   README update is consistent.
   Action needed: please rebase onto the latest plugin branch (after fix(memos-local-openclaw): normalize Windows paths when resolving better-sqlite3 #1265 lands), remove the index.ts diff, and keep only the Gemini changes (gemini.ts + README.md). Happy to merge once that's done.