fix incorrect 'drafts' folder view

CHANGELOG.md

@@ -1,5 +1,18 @@
 # Changelog
 
+# 2026-10-06
+
+- **The Drafts tab showed the Inbox** — "Drafts" is in `defaultTabOrder`, so it
+  renders as a regular tab, but `activeFolder()`'s label→mailbox switch had no
+  `"Drafts"` case: every unmatched label fell through to `default` and fetched
+  the Inbox mailbox, so the tab displayed Inbox mail no matter what the webmail
+  showed in the real Drafts folder. Only the tab was affected — `gd` (off-tab
+  Drafts view) maps through a separate switch and was always correct. Added the
+  missing case (`internal/ui/model.go`, `activeFolder`). Side effect: `S` /
+  `:screen` now correctly refuse on the Drafts tab (`onPlainInboxTab`), where
+  they previously misidentified it as the Inbox. Test:
+  `TestActiveFolderDraftsTab`.
+
 # 2026-10-05
 
 - **The folder window is the newest mail by arrival date, not the highest UIDs (#34)** — `FetchHeaders` picked its `inbox_count` window as the highest `n` UIDs. IMAP MOVE/COPY give a message a fresh, highest UID in the destination mailbox (RFC 9051 per-mailbox UIDs), so every mail bulk-moved *into* a folder — `I` approve on ToScreen, `:reset-toscreen`, `U` undo — landed above all real recent mail, filled the window, and pushed the recent mail below the cutoff where no display sort (`,m`) could bring it back. Only folders with more than `inbox_count` messages were affected, which is why a HEY-style Inbox of a dozen rows never showed it while a 12'000-mail legacy Inbox after its first screening did (reproduced on Hostpoint/Dovecot, so not an Infomaniak quirk; the demo's `moves.log` shows `ToScreen uid=273 → INBOX destUID=1397`). `FetchHeaders`, `FetchLatest` (`:everything`) and the per-folder search cap (`searchFolderCap`, was a literal 100) now narrow the window with one cheap `UID FETCH (UID INTERNALDATE)` and keep the `n` most recently received (`newestUIDsByInternalDate`, `internal/imap/client.go`); INTERNALDATE survives MOVE/COPY on every server tested, and the SORT extension is not used because Infomaniak does not offer it. Folders at or below `inbox_count`, and `inbox_count = 0`, take the old single-round-trip path unchanged, so a daily Inbox sees no new traffic. Verified on the live Hostpoint demo: a 10-row window returned April mail before, October mail after. Tests: `TestMem_FetchHeaders_WindowIsNewestByInternalDateNotUID`, `TestMem_FetchHeaders_FolderWithinLimitUnchanged`, `TestMem_FetchLatest_WindowIsNewestByInternalDateNotUID`, `TestMem_SearchFolder_CapIsNewestByInternalDateNotUID`.

internal/ui/model.go

@@ -1134,6 +1134,8 @@ func (m Model) activeFolder() string {
 		return m.cfg.Folders.Sent
 	case "Trash":
 		return m.cfg.Folders.Trash
+	case "Drafts":
+		return m.cfg.Folders.Drafts
 	case "Archive":
 		return m.cfg.Folders.Archive
 	case "Waiting":

internal/ui/model_test.go

@@ -457,6 +457,25 @@ func TestActiveFolderUsesOffTabFolder(t *testing.T) {
 	}
 }
 
+// TestActiveFolderDraftsTab — the Drafts tab (in defaultTabOrder) must fetch
+// the Drafts mailbox; the label switch in activeFolder() had no Drafts case,
+// so the tab fell through to default and showed the Inbox instead.
+func TestActiveFolderDraftsTab(t *testing.T) {
+	m := Model{
+		cfg: &config.Config{
+			Folders: config.FoldersConfig{
+				Inbox:  "INBOX",
+				Drafts: "Drafts",
+			},
+		},
+		folders:       []string{"Inbox", "Drafts"},
+		activeFolderI: 1,
+	}
+	if got := m.activeFolder(); got != "Drafts" {
+		t.Fatalf("activeFolder() on the Drafts tab = %q, want %q (must not fall back to the Inbox)", got, "Drafts")
+	}
+}
+
 func TestUpdateInboxEscClearsCommittedFilter(t *testing.T) {
 	m := Model{
 		filterText: "invoice",