v2.0.0-rc.3

Release candidate 3.

This RC surfaces a missing Vectorize index at runtime, so a one-click deploy that could not create the index is no longer silently broken. The deploy itself is unchanged; the running Worker now reports and works around the missing index.

What's new since rc.2:

• New GET /health endpoint that reports Vectorize index status ({ ok, vectorize: { ok, indexName, dimensions, error } }).
• Recall degrades to keyword-only search with a clear notice instead of failing when the index is missing. The notice appears in both the MCP recall tool and GET /recall.
• The web dashboard shows a warning banner with fix instructions when the index is missing.
• README: a new "Enable semantic search" troubleshooting section covering the wrangler vectorize create one-liner and the dashboard permission path, plus a /health verify step.

Notes:

• Deploy and capture behavior are unchanged. Memories captured while the index is missing are stored in D1 and stay pending until the index exists.
• Full test suite passing (494 tests), typecheck clean.

This is a pre-release for RC testing. It is not a stable release.