feat: ag init — zero-config onboarding with smart defaults and single-command startup

[OneStepAt4time]

Summary

ag init already exists and scaffolds a project interactively. This issue tracks the zero-config experience: a user should be able to go from npx @onestepat4time/aegis init to a running dashboard with zero manual config on localhost.

Current State

ag init already:

• Scaffolds .aegis/config.yaml
• Generates API keys
• Creates state directory
• Detects localhost → zero-config mode (feat(init): zero-config default — no token on localhost (F1, F2) #3496)
• Has template gallery (--list-templates, --from-template)

Problem

From #3181 (install friction):

• Users still hit configuration decisions on first run
• Auth token setup is confusing for solo dev use case
• No clear "next steps" after init completes
• ag run after init should "just work" but often requires manual config edits

Acceptance Criteria

Must-have

• ag init with all defaults (no flags, no prompts on localhost) completes in <30 seconds
• After init, ag run starts successfully without any manual config
• Init output prints the dashboard URL and a working auth token
• Init validates Claude Code is installed and offers to install if missing (already partially in ensureClaudeInstalled)
• Non-localhost shows minimal interactive prompts (URL, token) — no overwhelming questionnaire
• Tests: E2E init → run flow on fresh directory, verify config is valid

Nice-to-have

• ag init --yes flag for fully non-interactive (CI-friendly)
• Smart port detection (find free port, write to config)
• Post-init health check (verify dashboard loads, Claude responds)

Scope

• Backend (CLI) — src/commands/init.ts, src/commands/run.ts
• Related: feat: reduce install friction — target 2-command setup (npx + ag run) #3181 (install friction root issue)
• No dashboard changes

Dependencies

• None — can start immediately

Design Notes

• Solo dev on localhost should see zero prompts. Period.
• The target user (from strategic refocus): solo dev running 1-100 CC agents on their own machine
• If init asks more than 2 questions on localhost, we failed

[aegis-gh-agent]

Resolved by PR #4450 (merged on 2026-05-29). All 6 acceptance criteria verified by integration tests. Closing.