Phase 4: email assistant (IMAP/SMTP)

[Copilot]

Implements the email assistant module (super-ollama email ...) with full IMAP/SMTP integration, AI-assisted composition, and local draft persistence.

internal/mail package

• config.go — Loads ~/.super-ollama/mail.toml (host/port/username only). Passwords stored exclusively in the OS keyring via zalando/go-keyring under "super-ollama-mail". Exposes loaders for profile.md, prompts/email.md, and per-contact notes. Contact filenames use alphanumeric-only slugs to prevent path traversal.
• imap.go — ListMessages (headers-only, optional unread filter) and ReadMessage (full body by UID) via go-imap v1. Supports implicit TLS (port 993) and STARTTLS. TLS 1.2 minimum enforced.
• body.go — RFC-2822 body extraction: plain text, multipart/alternative, quoted-printable.
• smtp.go — Send via stdlib net/smtp; handles STARTTLS (587) and implicit TLS (465). TLS 1.2 minimum enforced.
• store.go — SQLite (mail.db) with emails and drafts tables. Pragmas applied via Exec rather than DSN string concatenation.
• prompt.go — Assembles LLM prompts from system prompt + user profile + contact notes + tone flag. Tone flags: formal / casual / brief.

CLI subcommands (cmd/super-ollama/email.go)

Replaces the existing stub with a real parent command and seven sub-commands:

super-ollama email setup                                          # store credentials in keyring
super-ollama email list [--unread] [--n 20]                       # fetch INBOX headers
super-ollama email read --message-id <uid>                        # display full message
super-ollama email compose --to <addr> --subject <subj> [--tone formal|casual|brief] [--draft]
super-ollama email reply   --message-id <uid> [--tone ...]        # auto-saves draft
super-ollama email summarise --message-id <uid>
super-ollama email send --draft-id <id> [--confirm]               # SMTP dispatch

Dependencies added

github.com/emersion/go-imap v1, go-smtp v0.21.3, go-message v0.18.1, go-sasl, github.com/zalando/go-keyring v0.2.5