Finish the RAG-index fan-out fix to match the regate-sweep isInstalled pattern

[JSONbored]

Part of #5016. Depends on #5028 (isInstalled reliability).

Problem

fanOutRagIndexJobs (src/queue/processors.ts:1144-1174) has a documented PARTIAL fix already in place (comment: "The union is the fix for the brokered self-host: a maintainer's repos are is_registered=0 ... left indexing without codebase context") — but it only unions isRegistered repos with the GITTENSORY_REVIEW_REPOS allowlist, unlike the regate sweep (fanOutAgentRegateSweepJobs) which unions ALL listRepositories(). Net effect: an installed repo that's neither gittensor-registered nor manually allowlisted gets reviewed (the regate sweep covers it) but never RAG-indexed — degraded review quality (no codebase-context retrieval), not a hard break.

Target

Drop the isRegistered branch entirely; start from all repos like the regate sweep. The existing convergedFeatureActive(env, repo, "rag") narrowing at the end already gates the real cost (embedding/indexing spend), so this change only widens ELIGIBILITY, not spend.

Priority

Low-medium — already partially mitigated today via the GITTENSORY_REVIEW_REPOS allowlist workaround, so this is a quality-of-life completion, not an active bug.

Deliverables

• Updated scoping in fanOutRagIndexJobs, comment corrected.
• Regression test: an installed, non-registered, non-allowlisted repo becomes eligible for RAG indexing once convergedFeatureActive says yes.
• Full local gate green, 99% patch coverage on the diff.

[linear-code]

JSO-3634