refactor: tidy up sharing after the round of tweaks

- Go to's picker settings are one picker struct, set while picking.
- Opening a share link plans the save, then asks or saves; no more
  offerWrite doing either by a flag.
- Closing the picker while it encrypts cancels the share, and a
  second pick meanwhile is ignored.
- Favourites and Recent leave out plain env values as keys too.
- share.key in the config is checked with share.ParseKey, so
  {{secrets/…}} is refused there already.
- A key that can't be read reads the same opening as sharing
  ("can't use …"); KeyError moved to share.go, maxFiles is
  maxUnpacked (bytes), and a stray comment is gone.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

internal/ui/app/searchview.go

@@ -53,16 +53,8 @@ type searchView struct {
 	res    int      // cursor in shown
 	here   string   // the scope of the source Go to was opened from, if any
 
-	// pick, if set, makes Go to a picker of secrets, for title: it lists
-	// secrets only, and enter gives the selected one's link to pick
-	// instead of going there.
-	pick        func(m *Model, r ref.Ref) tea.Cmd
-	pickTitle   string   // the popup's
-	pickLines   []string // what picking is for, above the picker
-	pickHeading string   // the picker's title, on its border
-	pickHelp    []string // inside it, above the tabs
-	pickBusy    string   // what picking is doing, under the help
-	pickErr     string   // why the key picked can't be used
+	// picker, if set, makes Go to pick a secret instead of going to it.
+	picker *picker
 
 	// loaded are the scopes a search has loaded since the popup opened:
 	// typing loads the scope once, so lists that fail aren't asked for
@@ -279,7 +271,7 @@ func (v *searchView) match() []option {
 			}
 		}
 	}
-	if v.pick != nil {
+	if v.picker != nil {
 		cand = slices.DeleteFunc(slices.Clone(cand), func(o option) bool { _, ok := pickable(o); return !ok })
 	}
 	q := v.input.Value()
@@ -438,13 +430,13 @@ func (m *Model) handleSearch(msg tea.KeyPressMsg) tea.Cmd {
 		return nil
 	case key.Matches(msg, k.sel):
 		switch {
-		case v.results && v.res < len(v.shown) && v.pick != nil:
+		case v.results && v.res < len(v.shown) && v.picker != nil:
 			r, _ := pickable(v.shown[v.res])
-			return v.pick(m, r) // the picker closes when it's done
+			return v.picker.choose(m, r)
 		case v.results && v.res < len(v.shown):
 			m.search = nil
 			return v.shown[v.res].run(m)
-		case !v.results && v.pick != nil:
+		case !v.results && v.picker != nil:
 			v.results = true // a picker only narrows to the scope
 		case !v.results && v.onSource():
 			m.search = nil
@@ -662,15 +654,14 @@ func (m Model) searchViewBox() string {
 	focused := !m.termBlurred
 	w := searchWidth(m.w)
 	popupW := w
-	if v.pick != nil {
+	if v.picker != nil {
 		w -= 4 // inside the picker's border, in the popup
 	}
 	listH := max(5, min(m.h-10, 14))
-	if v.pick != nil {
-		// What it's for, the help, the tabs and a border more.
+	if v.picker != nil {
 		// What it's for, the help, a line or two on the key picked, the
 		// tabs and a border more.
-		listH = max(5, min(m.h-10-len(v.pickLines)-len(v.pickHelp)-8, 14))
+		listH = max(5, min(m.h-10-len(v.picker.lines)-len(v.picker.help)-8, 14))
 	}
 
 	srcW := 10
@@ -765,16 +756,16 @@ func (m Model) searchViewBox() string {
 
 	ts := panes.TitleStyle(m.st, focused)
 	var body []string
-	if v.pick != nil {
-		for _, l := range v.pickHelp {
+	if p := v.picker; p != nil {
+		for _, l := range p.help {
 			body = append(body, " "+l)
 		}
 		switch {
-		case v.pickBusy != "":
-			body = append(body, "", " "+m.st.Notice.Render(v.pickBusy))
-		case v.pickErr != "":
+		case p.busy != "":
+			body = append(body, "", " "+m.st.Notice.Render(p.busy))
+		case p.err != "":
 			body = append(body, "")
-			for _, l := range strings.Split(ansi.Wordwrap(v.pickErr, w-4, " "), "\n") {
+			for _, l := range strings.Split(ansi.Wordwrap(p.err, w-4, " "), "\n") {
 				body = append(body, " "+m.st.Error.Render(l))
 			}
 		}
@@ -810,25 +801,46 @@ func (m Model) searchViewBox() string {
 	}
 	// Tabs in the title, the current one underlined, like the panes; a
 	// picker has its own title, and the tabs over the input.
-	head := ts.Render(goToTitle+" ") + m.goToTabs(ts)
-	if v.pick == nil {
+	if v.picker == nil {
+		head := ts.Render(goToTitle+" ") + m.goToTabs(ts)
 		return panes.Box(m.st, head, foot, body, w, len(body)+2, focused)
 	}
 	// A picker: in its own border, under what it's for.
 	var outer []string
-	for _, l := range v.pickLines {
+	for _, l := range v.picker.lines {
 		outer = append(outer, " "+l)
 	}
 	outer = append(outer, "")
-	for _, l := range strings.Split(panes.Box(m.st, ts.Render(v.pickHeading), "", body, w, len(body)+2, focused), "\n") {
+	for _, l := range strings.Split(panes.Box(m.st, ts.Render(v.picker.heading), "", body, w, len(body)+2, focused), "\n") {
 		outer = append(outer, " "+l)
 	}
-	return panes.Box(m.st, ts.Render(v.pickTitle), foot, outer, popupW, len(outer)+2, focused)
+	return panes.Box(m.st, ts.Render(v.picker.title), foot, outer, popupW, len(outer)+2, focused)
+}
+
+// picker is Go to picking a secret for something (the key to share
+// with): it lists secrets only, and enter hands the selected one's link
+// to pick, which closes Go to when it's done with it.
+type picker struct {
+	pick    func(m *Model, r ref.Ref) tea.Cmd
+	title   string   // the popup's
+	lines   []string // what picking is for, above the picker
+	heading string   // the picker's title, on its border
+	help    []string // inside it, above the tabs
+	busy    string   // what the pick is doing (picks wait meanwhile)
+	err     string   // why the secret picked can't be used
+}
+
+// choose hands r to the picker, unless it's still busy with one.
+func (p *picker) choose(m *Model, r ref.Ref) tea.Cmd {
+	if p.busy != "" {
+		return nil
+	}
+	return p.pick(m, r)
 }
 
 // selectLabel names what enter does with the selected entry.
 func (v *searchView) selectLabel() string {
-	if v.pick != nil {
+	if v.picker != nil {
 		return "pick"
 	}
 	return "go"