v1.8.1

## Bug Fixes

### Windows: OpenCode setup writes to correct path (#39)
`engram setup opencode` now writes to `~/.config/opencode/` on Windows instead of `%APPDATA%\opencode\`, matching where OpenCode actually reads its config.

### Gemini CLI: fix system prompt error outside $HOME (#31)
Removed `GEMINI_SYSTEM_MD=1` from `~/.gemini/.env` — it caused Gemini CLI to look for `system.md` relative to CWD instead of `~/.gemini/`. Re-running `engram setup gemini-cli` will clean up the stale env var from previous installs.

### TUI: timestamps now show local time (#27)
All timestamps in `engram tui` are now converted from UTC to the user's local timezone before display.

### Memory: raise observation limit and warn on truncation (#41)
Default `MaxObservationLength` raised from 2,000 to 50,000 characters. When content is still truncated, the MCP response now includes a warning with the original and stored sizes so agents can react (split into smaller observations, etc.) instead of silently losing data.