feat: a Not spam action

Backlog item 201. A message in the Spam view had no way back out: spam is
one-way and Restore is hidden outside the trash. not_spam moves each message
to the folder its moved-from: origin names, falling back to the account's
inbox (reported) for provider-caught mail with no origin.

The action is labelled "Not junk" on the free Alt+J: every letter of "Not
spam" is taken in the Message menu, and Alt+P (Re&ply) and Alt+S (Mark &spam,
frozen) are unavailable.

restoreResolvedMessages() and the undelete_thread branch are parameterised
with the cleared tag and undo description rather than copied, so Delete and
Not spam cannot drift.

1 files changed, 33 insertions, 3 deletions

diff --git a/docs/superpowers/plans/2026-09-13-spam-view.md b/docs/superpowers/plans/2026-09-13-spam-view.md
index f6bec47..ebd8a6a 100644
--- a/docs/superpowers/plans/2026-09-13-spam-view.md
+++ b/docs/superpowers/plans/2026-09-13-spam-view.md
@@ -460,9 +460,39 @@ lupdate-qt6 src/ -ts translations/qtmaildir_it_IT.ts -no-obsolete -locations non
 
 ---
 
+### Task 9: Not spam
+
+**Files:**
+- Modify: `src/keymap.cpp` (`knownActions()`)
+- Modify: `src/mainwindow.h` (`notSpamSelected()`, `notSpamMessages()`, `notSpamThreads()`, `everySelectedRowIsInASpamFolder()`)
+- Modify: `src/mainwindow.cpp` (action, icon table, both menus, message-bar spam branch, gating, the three methods, the `not_spam_*` resolution branches)
+- Modify: `tests/test_mainwindow.cpp`
+- Modify: `CHANGELOG.md`, `README.md`, `translations/qtmaildir_it_IT.ts`
+
+**Interfaces:**
+- Consumes: `Account::spam`, `accountForMessagePath()`, `originTagFor()`, `sendMove()`, the `resolveMessages`/`resolveThreadMessages` worker calls, `kOriginTagPrefix`, `m_replySelectionHidesDelete`.
+- Produces: `MainWindow::notSpamSelected()`, `notSpamMessages(const QStringList &, const QStringList &, const QStringList &)`, `notSpamThreads(const QStringList &)`, `bool MainWindow::everySelectedRowIsInASpamFolder() const`.
+
+**Behaviour (approved 2026-09-14).** Shown when the selection is in a spam folder, hidden on reply rows and in the trash, like Delete/Restore. Moves each message back to the folder its `moved-from:` tag names, strips `spam` + that origin, adds `inbox` when the destination is the account's inbox. A message with NO origin (provider-caught) falls back to the account's inbox and is reported in the status bar, exactly as `restoreResolvedMessages()` already does for trash. A conversation row acts on the whole conversation, a message row on that message. Undoable, no confirmation, no default shortcut.
+
+- [ ] **Step 1: Register.** Add `QStringLiteral("not_spam")` to `KeyMap::knownActions()`, no `defaultBindings()` entry. Icon table: `{ QStringLiteral("not_spam"), { QStringLiteral("mail-mark-notjunk"), QString() } }` (`mail-mark-notjunk` ships in Breeze and Adwaita and is unused in the table, so no icon exception is needed).
+- [ ] **Step 2: Action + menus.** `addAction(QStringLiteral("not_spam"), tr("Not s&pam"), ...)` with tip `tr("Move the selected messages out of the spam folder")`; choose a mnemonic free in the Message menu (`&p` is `Re&ply`, `&s` is `Mark &spam`; `noMenuHasTwoEntriesSharingAMnemonic()` must stay green). Add the action to `messageMenu` and `m_threadContextMenu`.
+- [ ] **Step 3: Predicate + gating.** Add `bool MainWindow::everySelectedRowIsInASpamFolder() const` mirroring `everySelectedRowIsInATrashFolder()` but comparing against `account.spam`. In `refreshTrashActions()` compute `const bool inSpam = everySelectedRowIsInASpamFolder();` and set `not_spam` visible with `haveSelection && inSpam && !m_replySelectionHidesDelete`, so it is hidden on a reply row and everywhere outside the spam folder.
+- [ ] **Step 4: Message bar.** In `populateMessageBar()`, add a branch keyed on `everySelectedRowIsInASpamFolder() && !selection empty`, between the trash branch and the draft branch, whose list is `{ not_spam }`.
+- [ ] **Step 5: The three methods.** `notSpamSelected()` mirrors `restoreSelectedFromTrash()` but resolves through the worker with request tag `"not_spam_messages"`; `notSpamThreads()` mirrors `untrashThreads()` with `"not_spam_thread"`. Handle both in `onThreadMessagesResolved()` beside `"restore_messages"` and `"undelete_thread"`, clearing `spam` instead of `deleted`. **Prefer parameterising the existing `restoreResolvedMessages()` and the `undelete_thread` branch with the cleared tag and the undo description over copying them**, so the two scopes cannot drift; if you copy instead, say why.
+- [ ] **Step 6: Tests** in `tests/test_mainwindow.cpp`, `WorkerBackedWindow`, `QTRY_VERIFY_WITH_TIMEOUT`, assertions against the database:
+  - mark a message spam, then Not spam: the file returns to its exact original folder, `spam` and `moved-from:` are gone, and `inbox` is back when the origin is the inbox;
+  - a provider-caught message (in the spam folder, no `moved-from:`) goes to the account's inbox and the status reports that it had no origin;
+  - visibility: offered in the spam view, hidden on a reply row and in the trash view;
+  - undo restores it.
+- [ ] **Step 7: Docs + i18n.** Add a clause to the changelog's `[Unreleased]` Added entry, mention the action in `README.md`, run `lupdate-qt6`/`lrelease-qt6`, translate the new strings, and keep `ctest -R translations` green.
+- [ ] **Step 8: Run + commit.** `ctest --test-dir build -R 'keymap|mainwindow|translations'`, then `git commit -S -m "feat: a Not spam action"`.
+
+---
+
 ## Self-review
 
-- **Spec coverage:** config key + queries (Task 1), the Spam filter (Task 2), origin rename (Task 3), the move action (Task 4), message bar + icon (Task 5), Empty Spam (Task 6), stranded cleanup (Task 7), translations/docs (Task 8). The trash-predicate test is in Task 4 Step 6. Item 196 (abusectl auto-tagging) and item 197 (not-spam) are out of scope by the spec.
-- **Type consistency:** `spamQuery`/`allSpamQuery`/`isShowingSpam`/`spamSelected`/`spamMessages`/`spamThreads`/`emptySpam`/`showStrandedSpamMail`/`kOriginTagPrefix` are used with one spelling throughout.
-- **Decided:** Empty Spam removes `spam`, `unread` and `inbox` (user confirmed `unread`), and adds `deleted` + the origin placeholder. It carries no confirmation dialog and no default shortcut; it is a move and is undoable.
+- **Spec coverage:** config key + queries (Task 1), the Spam filter (Task 2), origin rename (Task 3), the move action (Task 4), message bar + icon (Task 5), Empty Spam (Task 6), stranded cleanup (Task 7), translations/docs (Task 8), Not spam (Task 9, added 2026-09-14 from backlog item 201 after the branch's final review). The trash-predicate test is in Task 4 Step 6. Item 196 (abusectl auto-tagging) and item 197's provider-notification half are out of scope by the spec; item 197's destination question is settled as the inbox fallback in Task 9.
+- **Type consistency:** `spamQuery`/`allSpamQuery`/`isShowingSpam`/`spamSelected`/`spamMessages`/`spamThreads`/`emptySpam`/`showStrandedSpamMail`/`notSpamSelected`/`notSpamMessages`/`notSpamThreads`/`everySelectedRowIsInASpamFolder`/`kOriginTagPrefix` are used with one spelling throughout.
+- **Decided:** Empty Spam removes `spam`, `unread` and `inbox` (user confirmed `unread`), and adds `deleted` + the origin placeholder. It carries no confirmation dialog and no default shortcut; it is a move and is undoable. Not spam falls back to the account's inbox for provider-caught mail, at the user's decision on 2026-09-14.
 - **Known blast radius:** Task 3 renames a string literal in ~35 test sites; `grep -rn "deleted-from" src tests` must be empty afterwards.