docs: add hosted Alpha Loop setup guide for websites and apps

[bradtaylorsf]

Summary

Write a complete hosted Alpha Loop setup guide for websites and web applications, including server setup, GitHub configuration, safety policy, event destinations, feedback ingestion, and first-run workflows.

Why this matters

Hosted Alpha Loop will only be trustworthy if another team can install it, understand what it will and will not do, configure guardrails, connect notifications, and recover from common problems without reading the code. Documentation is part of the product surface for a 24/7 worker.

Proposed approach

• Add a hosted setup guide under docs/ and link it from README.
• Cover prerequisites: Node, pnpm, git, GitHub CLI/auth, agent CLI, Playwright/browser dependencies, server filesystem layout, and secrets.
• Explain repo-local installation and config ownership: Alpha Loop as a dev dependency plus .alpha-loop.yaml and repo templates.
• Include safe starter configs for marketing sites and web apps.
• Explain automation policy, allowed/protected paths, command allowlists, session limits, and human gates.
• Explain events/destinations with Slack, Teams, Discord, email-via-script, and custom webhook examples.
• Explain feedback ingestion and resume: GitHub comments as canonical source, adapters as optional bridges, and how resume --issue works.
• Include operational docs: daemon startup, systemd/Docker examples, logs, health checks, pausing, cleanup, budgets, and troubleshooting.

Acceptance criteria

• README links to a hosted Alpha Loop setup guide.
• Guide explains repo setup, server setup, GitHub auth, labels, issue templates, secrets, browser dependencies, and first run.
• Guide includes a safe starter .alpha-loop.yaml for a website/web app.
• Guide includes Slack, Teams, Discord, email script, and custom webhook destination examples.
• Guide explains feedback ingestion, issue resume, paused worktrees, and human QA handoff.
• Guide documents recommended labels and when humans should apply ready.
• Guide documents operational tasks: logs, health checks, cleanup, budgets, pausing, and troubleshooting.
• Docs tests or link checks cover the new guide and README references.

Out of scope

• A hosted SaaS onboarding wizard.
• Provider-specific deployment automation.
• Native Slack app installation docs beyond webhook/adapter examples.

Related

• Parent epic: Epic: Hosted Alpha Loop for 24/7 repo stewardship with human feedback loops #293
• Should be updated as each hosted capability lands.

[bradtaylorsf]

Part of #293