Draft with Claude proposes a title too (closes #316) c43e4f631d99

- **The new proposal form lines up (#315):** as wide as the changes above it; Draft with Claude a secondary button under the editor (it fills the fields, it does not open the proposal); the draft checkbox and Open proposal on one row.

- **Draft with Claude proposes a title too (#316):** for a proposal not yet opened, the assistant begins its draft with a title in the style of the changes' own titles; it fills the title field unless you wrote one (the page's own suggestion does not count), and stays out of the description.

      // A new proposal's draft begins with its title line (#316): kept out

      // of the description, and put in the title unless the person wrote one.

      var titleField = form.querySelector('input[name="title"]');

      function untitled(t) { return t.replace(/^\s*title:[^\n]*(\n\s*|$)/i, ""); }

                if (kind === "part") { text += v; show(untitled(text)); }

                else if (kind === "title") {

                  if (titleField && (!titleField.value.trim() || titleField.value === titleField.defaultValue)) titleField.value = v;

                }

    /// #316: a new proposal's draft begins with its title line, kept apart

    /// from the description; a draft without one is all description.

    #[test]

    fn a_draft_s_title_line_is_split_off() {

        assert_eq!(

            split_title("Title: feat(flow): hand jobs back\n\n**Summary.** Runners leave."),

            (Some("feat(flow): hand jobs back".to_string()), "**Summary.** Runners leave.".to_string())

        );

        assert_eq!(split_title("  title: \"Quoted\"\nBody"), (Some("Quoted".to_string()), "Body".to_string()));

        assert_eq!(split_title("**Summary.** No title here."), (None, "**Summary.** No title here.".to_string()));

        assert_eq!(split_title("Title:\nBody"), (None, "Body".to_string()), "an empty title is none");

    }

/// The system prompt for drafting a proposal's description; `with_title`,

/// for a proposal not yet opened, asks for a title line first (#316).

pub fn draft_system_prompt(a: &Assistant, site: &str, prompts: &str, with_title: bool) -> String {

    let shape = if with_title {

        "Begin with one line `Title: ` and a title of at most 72 characters, in the style of the changes' own titles \

         (Conventional Commits if they use them), then a blank line, then the description in Markdown: \

         no greeting, no sign-off."

    } else {

        "Write Markdown for the description field only: no title line, no greeting, no sign-off."

    };

         {shape} \

    /// A proposal not yet opened: the draft begins with a title line (#316).

    pub with_title: bool,

}

/// A draft's `Title: …` first line, if it has one, and the description

/// after it (#316).

pub fn split_title(text: &str) -> (Option<String>, String) {

    let text = text.trim_start();

    let (first, rest) = text.split_once('\n').unwrap_or((text, ""));

    let Some(t) = first.trim().strip_prefix("Title:").or_else(|| first.trim().strip_prefix("title:")) else {

        return (None, text.trim().to_string());

    };

    let t: String = t.trim().trim_matches(|c| c == '"' || c == '`' || c == '*').trim().chars().take(120).collect();

    ((!t.is_empty()).then_some(t), rest.trim().to_string())

    let Draft { slot, title, target, changes, diffs, with_title } = d;

            let system = draft_system_prompt(a, &app.config.site.name, &prompts, with_title);

    let d =

        crate::assistants::Draft { slot: -row.id, title: &f.title, target: &f.target, changes: &changes, diffs: &diffs, with_title: true };

        Ok(text) => {

            let (title, body) = crate::assistants::split_title(&text);

            page.body = body;

            // The title too, unless the person wrote one (#316): the page's

            // own suggestion, a single change's title, counts as theirs not.

            let suggested = if page.preview.len() == 1 { page.preview[0].title.clone() } else { String::new() };

            if let Some(t) = title.filter(|_| page.title.trim().is_empty() || page.title.trim() == suggested.trim()) {

                page.title = t;

            }

        }

    let d = crate::assistants::Draft {

        slot: p.id,

        title: &title,

        target: &p.target,

        changes: &loaded.changes,

        diffs: &loaded.diffs,

        with_title: false,

    };

    /// Not yet opened: the draft proposes a title too (#316).

    with_title: bool,

        let DraftJob { row, by, a, slot, title, target, changes, diffs, with_title } = job;

        let d = crate::assistants::Draft { slot, title: &title, target: &target, changes: &changes, diffs: &diffs, with_title };

            Ok(text) if with_title => {

                // The title first, for the page to put in its field (#316).

                let (t, body) = crate::assistants::split_title(&text);

                if let Some(t) = t {

                    let _ = tx.send(draft_event("title", &t)).await;

                }

                draft_event("done", &body)

            }

        with_title: false,

    let job = DraftJob {

        slot: -row.id,

        row,

        by: me.account.clone(),

        a,

        title: f.title.clone(),

        target: f.target.clone(),

        changes,

        diffs,

        with_title: true,

    };

        // A proposal not yet opened gets a title too (#316); the person's own is kept.

        assert!(calls[0].contains("Begin with one line `Title: `"), "{}", calls[0]);