cairn/log/2026-07-30-wizard-discovery-only.md
Made the configuration wizard configure an account only from what it can discover automatically, and deleted every hand-entry path. An email, a bare domain and a scheme:// server URL now all run discovery through a single configure_discovery: a URL discovers from its host, and its scheme narrows the results — imap/imaps keep IMAP + SMTP (with imaps requiring an implicit-TLS IMAP endpoint), the HTTP-family schemes keep JMAP, and proprietary Gmail/Graph entries are dropped when a scheme is named. When discovery yields nothing (empty result, deadline elapsed, or scheme filter emptied) the wizard stops with a message pointing at the documented sample config, rather than prompting for fields.
Removed the hand-entry surface: manual_fallback, configure_server and split_email from wizard/discover.rs, configure_manual + prompt_smtp_endpoint + default_smtp + the seed_imap/wizard_imap_server helpers from wizard/imap_smtp.rs, and configure_manual from wizard/jmap.rs. That left wizard/account.rs (the WizardImapConfig/WizardSmtpConfig → config converters) dead except for two pub(crate) secret builders shared with wizard/secret.rs; those two moved into secret.rs (with their rejection tests) and account.rs was deleted.
The wizard no longer invents an SMTP host. IMAP was already never guessed — no discovered IMAP means no entry — but SMTP fell back to smtp.<domain> and then failed its own connection test when that host did not exist (the #722 shape). Now configure_discovered returns an optional SMTP config, and Chosen::ImapSmtp carries Option<Box<SmtpConfig>>: discovery with IMAP but no submission endpoint yields an IMAP-only account, no SMTP block and no SMTP test.
The local folder path now auto-detects the store kind from on-disk markers (.m2store/.m2dir → m2dir, cur/new/tmp → Maildir) and only prompts Maildir-vs-m2dir when both backends are compiled in and the directory is ambiguous.
Moved the wizard capability: MODIFIED "Input orients the flow", "Discovery is time-bounded", "One entry per service, then auth" and "Per-protocol test and shared SMTP credentials"; ADDED "Stop when nothing is discovered" and "Local backend auto-detected".
Verified: default build and all single-backend feature combinations compile, cargo fmt/clippy clean, and the wizard unit tests pass (including the two secret-builder tests that moved into secret.rs).