fix: address 5 bugs in CLI backend and postinstall patch

feat: add CLI LLM backend + fix standalone binary native addon crash

docs: update llm.ts header to mention Bedrock provider

Update bun.lock with @ai-sdk/amazon-bedrock and dependency updates

fix: update error recovery messages to mention all LLM providers

fix: add bedrock support to doctor command health checks

fix: bedrock provider defensive guards and fallback order

feat: add AWS Bedrock as LLM provider

fix: normalize resolved paths back to portable defaults in saveConfig

fix: expand tilde in XDG_DATA_HOME before path join

feat: add XDG Base Directory and CASS_MEMORY_HOME support

fix(semantic): auto-strip Xenova/ prefix when using Ollama backend

fix(serve): return JSON-RPC errors for tool call failures instead of MCP result wrapper

fix(test): stabilize flaky concurrent writes test

feat(semantic): add Ollama as alternative embedding backend