v1.12.0

## What's New

Engram now nudges agents that forget to save memories, and shows an activity score at session end so you can spot sessions with potential context loss.

## Features

### Save Reminder on Inactivity

When no `mem_save` has been called for 10+ minutes in an active session, engram appends a short reminder to `mem_search` and `mem_context` responses:

> No mem_save calls for this project for 15 minutes. Did you make any decisions, fix bugs, or discover something worth persisting?

Cost: ~30 tokens per nudge. Works with any MCP agent.

### Session Activity Score

When `mem_session_summary` is called, engram appends an activity score:

> Session activity: 47 tool calls, 2 saves

If the session had high activity but zero saves, it flags it:

> Session activity: 31 tool calls, 0 saves -- high activity with no saves, consider persisting important decisions

### DELETE /sessions and /prompts endpoints

New HTTP endpoints for hard-deleting sessions and prompts (PR #174 by @egdev6):
- `DELETE /sessions/{id}` -- deletes session and its prompts, returns 409 if it has observations
- `DELETE /prompts/{id}` -- deletes a single prompt

### Documentation overhaul

- Fixed Go version requirement (1.25 does not exist)
- Fixed module path in docs
- Added 3 missing HTTP endpoints to docs
- Added `obsidian-export` CLI command to all doc pages
- Restructured DOCS.md from 690-line mega-doc to focused ~400-line technical reference
- Deduplicated CLI and MCP tools references across files

## Upgrade

```bash
brew update && brew upgrade engram
```

## Links

- [Full changelog](https://github.com/Gentleman-Programming/engram/compare/v1.11.0...v1.12.0)
- [Documentation](https://github.com/Gentleman-Programming/engram/blob/main/DOCS.md)