fix(sdk): add repository metadata for npm provenance

[lukeocodes]

Summary

@deepgram/agents@0.1.0 publish failed at the npm provenance step:

npm error 422 Unprocessable Entity - PUT https://registry.npmjs.org/@deepgram%2fagents
Error verifying sigstore provenance bundle: Failed to validate repository information:
package.json: "repository.url" is "", expected to match "https://github.com/deepgram/agent" from provenance

npm provenance requires repository.url in package.json to match the source repo from the GitHub Actions build attestation. the SDK package.json had no repository field.

Changes

• packages/sdk/package.json: add repository (with directory: packages/sdk for monorepo awareness), homepage, and bugs.
• release-please-config.json: drop release-as: "0.1.0" from the SDK package. now that 0.1.0 is tagged, release-please should resume normal pre-major bump rules. this fix will land as 0.1.1.

State on main

• agents-v0.1.0 GitHub release exists but @deepgram/agents@0.1.0 is not on npm (provenance check rejected the upload).
• after this PR merges, release-please will open a new PR for SDK 0.1.1. merging that runs publish-sdk again with the repository field present, which should pass provenance.

Test plan

• bun run typecheck clean
• bun run build clean
• bun run test 78/78 passing
• CI green on this PR
• release-please PR for SDK 0.1.1 publishes @deepgram/agents@0.1.1 to npm

Follow-up

• the phantom agents-v0.1.0 GitHub release/tag can be left as-is (no consumer ever saw it on npm) or deleted for cosmetic cleanup.
• widget will get the same repository field in the phase 4 PR.
• release-as: "0.1.0" for widget stays in config until widget's first tag.