Add optional digest companion app (recent-memory summaries to Slack/Discord)

[imonroe]

Summary

Adds an optional digest companion app that periodically posts a summary of recently added memories to a Slack or Discord channel — a lightweight way to resurface what you've been capturing. Adapts the OB1 / Open Brain daily/weekly digest recipe (backlog issue #50) to this server.

It's a separate, port-less CapRover app built from digest/, mirroring the existing backup/ app's cron-container pattern (so it can't destabilize the stateless main API).

How it works

Each scheduled run: fetch recent memories (REST) → filter to the look-back window → summarize (Claude, optional) → post to webhook.

• No LLM required: if ANTHROPIC_API_KEY is unset, the digest is a plain bulleted list (zero added cost). If set, it's one Claude call per run.
• Slack & Discord: webhook format auto-detected from the URL (text vs content), overridable.
• Self-contained: depends only on httpx (already pinned); nothing from app/ or the main image.
• Schedule is env-driven (DIGEST_CRON, default daily 08:00 UTC); DIGEST_RUN_ON_START=true triggers an immediate run to verify config.

Files

• digest/digest.py — pure, unit-testable helpers (parse_timestamp, memory_text, filter_recent, summarize_with_claude, build_digest with graceful fallback, format_payload/detect_format, fetch_memories, deliver) plus main().
• digest/entrypoint.sh — snapshots env for cron (crond jobs don't inherit it), builds /etc/crontabs/root from $DIGEST_CRON, optional run-on-start, streams the log to stdout.
• digest/Dockerfile (python:3.12-alpine + dcron), requirements.txt, captain-definition.

Tests

• tests/test_digest.py — 17 cases: timestamp parsing (Z/naive/bad), filter_recent (recent vs old vs missing-timestamp, updated_at preference), text extraction, prompt/format/detect helpers, and respx-mocked fetch_memories (bearer + limit), deliver, summarize_with_claude (headers + parsing), build_digest (Claude path, no-key fallback, error fallback), and main() wiring (delivers when recent; skips when nothing new).
• Full suite: 119 passed, ruff clean.
• Also smoke-tested directly: required-env guard exits non-zero, entrypoint.sh passes sh -n, crontab line generates correctly, and print-mode (no webhook) renders the fallback digest.

Docs

• User Guide: new "3. Deploy the digest app (optional)" section with full env-var table, cost note, and a docker run example for non-CapRover hosts; plus a troubleshooting row.
• Developer Guide: project-layout entry. CLAUDE.md: companion-app note.

Architecture notes

No changes to the main app, its invariants, or runtime deps. The digest is a read-only REST consumer in its own container.

Closes #50.

https://claude.ai/code/session_017835DVrvURaYnbQiPQwzue

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Generated by Claude Code

[Copilot]

Pull request overview

Adds a new optional digest/ companion cron container that periodically fetches recent memories via the existing REST API, optionally summarizes them with Anthropic Claude, and posts the result to a Slack/Discord webhook (plus docs + tests to support deployment and behavior).

Changes:

• Introduces the standalone digest/ CapRover app (Dockerfile, entrypoint cron wiring, and digest.py helpers + main()).
• Adds a dedicated pytest suite for the digest behavior (pure helpers + respx-mocked network behavior).
• Updates user/developer documentation to describe deploying and operating the new digest companion app.

Reviewed changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
digest/digest.py	Implements digest fetching/filtering/summarization/delivery logic and env-driven main().
digest/entrypoint.sh	Cron container entrypoint: snapshots env, writes crontab, optional run-on-start, tails log.
digest/Dockerfile	Builds minimal Python + dcron Alpine image for the digest companion app.
digest/requirements.txt	Pins digest app runtime dependency (httpx).
digest/captain-definition	CapRover build descriptor for the digest app.
digest/__init__.py	Marks digest/ as a package for test imports.
tests/test_digest.py	Adds unit/integration-style tests (helpers + HTTP interactions via respx).
docs/USER_GUIDE.md	Documents optional digest deployment/configuration and troubleshooting.
docs/DEVELOPER_GUIDE.md	Updates project layout documentation to include digest/.
CLAUDE.md	Notes the new digest companion app in the repo overview.

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