Re-add Roo Code Router as an embeddings provider for codebase indexing

[hannesrudolph]

Roo Code Router (RCR) should be available as an embeddings provider option for codebase indexing. This was previously implemented and merged but had to be reverted due to two bugs: the codebase_search tool was leaking into the tool list even when indexing wasn't configured, and the embedder got stuck in "standby" when it was configured. Users authenticated with Roo Code Cloud should be able to use RCR for embeddings without needing a third-party API key.

Context

• Original implementation: Add support for Roo Code Cloud as an embeddings provider #9543 (merged Nov 24, 2025 by @mrubens)
• Revert: Revert "Add support for Roo Code Cloud as an embeddings provider" #9602 (merged Nov 26, 2025 by @mrubens)
• The original PR added a RooEmbedder class, CloudService auth integration, UI in CodeIndexPopover, model schema entries under the roo provider, localization strings, and tests. All removed by the revert.
• The original PR also set roo as the default embedder provider, which amplified the impact of both bugs since they affected all users, not just those who opted in.

[roomote]

I've analyzed this issue and the original PR (#9543) / revert (#9602) diffs in detail. Here's my proposed implementation plan:

Root Cause of the Original Bugs

1. codebase_search tool leak: The original PR set roo as the default embedder provider AND set codebaseIndexEnabled: true by default. This meant all authenticated Roo Code Cloud users had the codebase_search tool appear in their tool list even without explicitly enabling indexing.
2. Embedder stuck in "standby": The isConfigured() check for the roo provider depended on CloudService.hasInstance() and getSessionToken(), which could be in transient states during initialization (e.g., "attempting-session"). This caused the config check to oscillate, preventing the indexer from progressing past standby.

Proposed Changes

Re-introduce the Roo Code Router embeddings provider with these fixes:

1. Type Updates

• packages/types/src/codebase-index.ts: Add "roo" back to the codebaseIndexEmbedderProvider enum and codebaseIndexModelsSchema
• src/services/code-index/interfaces/manager.ts: Add "roo" to the EmbedderProvider union type

2. RooEmbedder Class (new file)

• src/services/code-index/embedders/roo.ts: Re-create the RooEmbedder class with OpenAI-compatible client, CloudService session token auth, base64 embedding decoding, batch processing, and rate limiting (same as original PR)

3. Config Manager (src/services/code-index/config-manager.ts)

• Add "roo" provider handling in _loadAndSetConfiguration()
• Add isConfigured() check for roo that uses CloudService.isAuthenticated() (a more stable check than raw session token parsing)
• Critical fix: Keep openai as the default provider (NOT roo) so unauthenticated or non-opt-in users are unaffected
• Critical fix: Keep codebaseIndexEnabled: false as default so the feature requires explicit opt-in

4. Service Factory (src/services/code-index/service-factory.ts)

• Import and wire up RooEmbedder for the "roo" provider case

5. Embedding Models (src/shared/embeddingModels.ts)

• Add roo provider profile with "text-embedding-3-small" (1536 dim) as default
• Add getDefaultModelId() case for "roo" provider

6. UI (webview-ui/src/components/chat/CodeIndexPopover.tsx)

• Add "roo" <SelectItem> in the provider dropdown (labeled "Roo Code Cloud")
• Add provider-specific UI section showing auth status and a sign-in prompt when not authenticated
• Add validation schema case for "roo" (no API key needed, just auth check)

7. Localization

• Add "rooAuthenticationRequired" string to embeddings.json in all 16 locale directories
• Add "rooCodeCloudProvider" label to settings.json locale files

8. Tests

• src/services/code-index/embedders/__tests__/roo.spec.ts: Re-create test suite for RooEmbedder (batch processing, rate limiting, error handling, base64 decoding)
• src/services/code-index/__tests__/config-manager.spec.ts: Add tests for roo provider configuration and isConfigured() auth check
• src/services/code-index/__tests__/service-factory.spec.ts: Add test for roo provider embedder creation

Bug Prevention Summary

Original Bug	Fix
codebase_search tool leaked for all users	roo is NOT the default provider; codebaseIndexEnabled defaults to false
Embedder stuck in standby	Use CloudService.isAuthenticated() instead of raw session token check; more stable auth state

Please mention @roomote in a comment saying that you approve this plan, and I'll proceed with the implementation.

[hannesrudolph]

@roomote I did not read your plan but sure go for it. verify that its solid.

[roomote]

I've seen your comment and will proceed with the implementation. I'll verify the plan is solid by examining the current codebase state, then implement the changes. I'll open a draft PR to share progress.

[roomote]

Opened a draft PR with my attempt at addressing this: #11298

Key changes:

• New RooEmbedder class using CloudService session token auth (no API key needed)
• "Roo Code Cloud" option in the codebase indexing provider dropdown with auth status UI
• Default provider remains openai (not roo) to prevent the original tool-leak bug
• Uses CloudService.isAuthenticated() for stable auth checks to prevent the standby bug
• 18 new tests covering the embedder, config-manager, and service-factory

Feedback welcome!