v0.177.2

Fix

• providers: retry only genuinely-transient Ollama transport errors
• providers: log a failed Ollama batch once, not once per retry attempt
• providers: log the batch shape on every Ollama embed failure
• providers: give Ollama the transient retry every other provider has
• providers: bound Ollama embed requests by characters, not item count
• vector: clear the dead-letter marker only after the upsert succeeds
• vector: dead-letter documents after repeated index failures