Add auto-saving draft with Save / Save As and Wipe

Editing the interlinearizer no longer writes to the active project on every
keystroke. Each source project now has an always-present draft
(draft:{sourceProjectId}) that auto-saves every edit to papi storage,
decoupled from the user's saved projects and never shown in the picker, so
work is never lost.

Persistence is now explicit:
- Save     writes the draft to the active project
- Save As  writes the draft to a new project, or overwrites an existing one
- New      starts an empty draft (a project is created only on Save As)
- Open     loads a project into the draft as a working copy
- Wipe     clears the draft — the current book or the whole thing

Switching projects (New / Open) while the draft is dirty prompts to discard.
The tab title shows a "●" marker while the draft has unsaved changes, toggled
via updateWebViewDefinition (Platform.Bible exposes no native unsaved-tab
indicator).

Implementation:
- DraftProject type + isDraftProject guard; getDraft/saveDraft storage with a
  per-source serialization queue; getDraft/saveDraft backend commands.
- useDraftProject hook owns the draft (autosave, dirty tracking, and a
  draftVersion that remounts the editor on New/Open/Wipe).
- New SaveAsProjectModal, WipeConfirm, and DiscardDraftConfirm; the New modal
  is repurposed to configure a draft rather than create a project.
- removeBookFromAnalysis util backs the per-book wipe.

Alignment links are intentionally not carried in the draft yet (no link-editing
feature exists); Save preserves a target project's existing links.

Deferred UX decisions are recorded in user-questions.md. 988 tests, 100%
coverage, lint clean.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: alex-rawlings-yyc

__mocks__/platform-bible-react.tsx

@@ -65,6 +65,42 @@ export const MOCK_VIEW_PROJECT_INFO_MENU_ITEM: MenuItemContainingCommand = {
   localizeNotes: '',
 };
 
+/** Sentinel menu item passed by the mock toolbar when the save button is clicked. */
+export const MOCK_SAVE_MENU_ITEM: MenuItemContainingCommand = {
+  label: '%interlinearizer_save%',
+  command: 'interlinearizer.save',
+  group: 'interlinearizer.file.actions',
+  order: 1,
+  localizeNotes: '',
+};
+
+/** Sentinel menu item passed by the mock toolbar when the save-as button is clicked. */
+export const MOCK_SAVE_AS_MENU_ITEM: MenuItemContainingCommand = {
+  label: '%interlinearizer_saveAs%',
+  command: 'interlinearizer.openSaveAsModal',
+  group: 'interlinearizer.file.actions',
+  order: 2,
+  localizeNotes: '',
+};
+
+/** Sentinel menu item passed by the mock toolbar when the wipe-book button is clicked. */
+export const MOCK_WIPE_BOOK_MENU_ITEM: MenuItemContainingCommand = {
+  label: '%interlinearizer_wipeBook%',
+  command: 'interlinearizer.wipeBook',
+  group: 'interlinearizer.draft.actions',
+  order: 1,
+  localizeNotes: '',
+};
+
+/** Sentinel menu item passed by the mock toolbar when the wipe-draft button is clicked. */
+export const MOCK_WIPE_DRAFT_MENU_ITEM: MenuItemContainingCommand = {
+  label: '%interlinearizer_wipeDraft%',
+  command: 'interlinearizer.wipeDraft',
+  group: 'interlinearizer.draft.actions',
+  order: 2,
+  localizeNotes: '',
+};
+
 
 /**
  * Stub toolbar that renders project-menu and view-info buttons using sentinel menu items so tests
@@ -127,6 +163,42 @@ export function TabToolbar({
           View project info
         </button>
       )}
+      {onSelectProjectMenuItem && (
+        <button
+          type="button"
+          data-testid="tab-toolbar-save"
+          onClick={() => onSelectProjectMenuItem(MOCK_SAVE_MENU_ITEM)}
+        >
+          Save
+        </button>
+      )}
+      {onSelectProjectMenuItem && (
+        <button
+          type="button"
+          data-testid="tab-toolbar-save-as"
+          onClick={() => onSelectProjectMenuItem(MOCK_SAVE_AS_MENU_ITEM)}
+        >
+          Save as
+        </button>
+      )}
+      {onSelectProjectMenuItem && (
+        <button
+          type="button"
+          data-testid="tab-toolbar-wipe-book"
+          onClick={() => onSelectProjectMenuItem(MOCK_WIPE_BOOK_MENU_ITEM)}
+        >
+          Wipe book
+        </button>
+      )}
+      {onSelectProjectMenuItem && (
+        <button
+          type="button"
+          data-testid="tab-toolbar-wipe-draft"
+          onClick={() => onSelectProjectMenuItem(MOCK_WIPE_DRAFT_MENU_ITEM)}
+        >
+          Wipe draft
+        </button>
+      )}
       {onSelectViewInfoMenuItem && (
         <button
           type="button"

contributions/localizedStrings.json

@@ -10,6 +10,10 @@
       "%interlinearizer_openSelectProjectModal%": "Select Interlinear Project…",
       "%interlinearizer_openNewProjectModal%": "New Interlinear Project…",
       "%interlinearizer_openProjectInfoModal%": "View Project Info…",
+      "%interlinearizer_save%": "Save",
+      "%interlinearizer_saveAs%": "Save As…",
+      "%interlinearizer_wipeBook%": "Wipe Current Book…",
+      "%interlinearizer_wipeDraft%": "Wipe Draft…",
 
       "%interlinearizer_projectSettings_title%": "Interlinearizer",
       "%interlinearizer_projectSettings_continuousScroll%": "Continuous Scroll",
@@ -71,11 +75,35 @@
       "%interlinearizer_modal_select_create_new%": "Create New",
       "%interlinearizer_modal_select_cancel%": "Cancel",
 
+      "%interlinearizer_confirm_discard_title%": "Discard unsaved changes?",
+      "%interlinearizer_confirm_discard_body%": "Your draft has changes that haven't been saved to a project. Continuing will discard them.",
+      "%interlinearizer_confirm_discard_ok%": "Discard",
+      "%interlinearizer_confirm_discard_cancel%": "Cancel",
+
+      "%interlinearizer_modal_saveAs_title%": "Save As",
+      "%interlinearizer_modal_saveAs_new_section%": "Save as a new project",
+      "%interlinearizer_modal_saveAs_save_new%": "Save as New Project",
+      "%interlinearizer_modal_saveAs_existing_section%": "Or overwrite an existing project",
+      "%interlinearizer_modal_saveAs_none%": "No existing projects for this source yet.",
+      "%interlinearizer_modal_saveAs_overwrite%": "Overwrite",
+      "%interlinearizer_modal_saveAs_overwrite_confirm_body%": "Overwrite this project? Its saved analysis will be replaced with the current draft.",
+      "%interlinearizer_modal_saveAs_overwrite_confirm_ok%": "Overwrite",
+      "%interlinearizer_modal_saveAs_overwrite_confirm_cancel%": "Cancel",
+      "%interlinearizer_modal_saveAs_cancel%": "Cancel",
+
+      "%interlinearizer_confirm_wipe_book_title%": "Wipe current book?",
+      "%interlinearizer_confirm_wipe_book_body%": "This removes all analysis for the current book from the draft. Save afterward to persist the change to a project.",
+      "%interlinearizer_confirm_wipe_draft_title%": "Wipe entire draft?",
+      "%interlinearizer_confirm_wipe_draft_body%": "This removes all analysis from the draft. Save afterward to persist the change to a project.",
+      "%interlinearizer_confirm_wipe_ok%": "Wipe",
+      "%interlinearizer_confirm_wipe_cancel%": "Cancel",
+
       "%interlinearizer_error_create_project_failed%": "Could not create the interlinearizer project. Please try again.",
       "%interlinearizer_error_save_metadata_failed%": "Could not save project info. Please try again.",
       "%interlinearizer_error_delete_project_failed%": "Could not delete the interlinearizer project. Please try again.",
       "%interlinearizer_error_update_project_failed%": "Could not update the interlinearizer project. Please try again.",
-      "%interlinearizer_error_load_projects_failed%": "Could not load interlinear projects. Please try again."
+      "%interlinearizer_error_load_projects_failed%": "Could not load interlinear projects. Please try again.",
+      "%interlinearizer_error_save_draft_failed%": "Could not save your working draft. Please try again."
     }
   }
 }

contributions/menus.json

@@ -27,6 +27,14 @@
           "interlinearizer.projectActions": {
             "column": "interlinearizer.project",
             "order": 1
+          },
+          "interlinearizer.fileActions": {
+            "column": "interlinearizer.project",
+            "order": 2
+          },
+          "interlinearizer.draftActions": {
+            "column": "interlinearizer.project",
+            "order": 3
           }
         },
         "items": [
@@ -50,6 +58,34 @@
             "group": "interlinearizer.projectActions",
             "order": 3,
             "command": "interlinearizer.openProjectInfoModal"
+          },
+          {
+            "label": "%interlinearizer_save%",
+            "localizeNotes": "Interlinearizer top menu > Save the current draft to the active project",
+            "group": "interlinearizer.fileActions",
+            "order": 1,
+            "command": "interlinearizer.save"
+          },
+          {
+            "label": "%interlinearizer_saveAs%",
+            "localizeNotes": "Interlinearizer top menu > Save the draft to a new project or overwrite an existing one",
+            "group": "interlinearizer.fileActions",
+            "order": 2,
+            "command": "interlinearizer.openSaveAsModal"
+          },
+          {
+            "label": "%interlinearizer_wipeBook%",
+            "localizeNotes": "Interlinearizer top menu > Remove the current book's analysis from the draft",
+            "group": "interlinearizer.draftActions",
+            "order": 1,
+            "command": "interlinearizer.wipeBook"
+          },
+          {
+            "label": "%interlinearizer_wipeDraft%",
+            "localizeNotes": "Interlinearizer top menu > Remove all analysis from the draft",
+            "group": "interlinearizer.draftActions",
+            "order": 2,
+            "command": "interlinearizer.wipeDraft"
           }
         ]
       }