fix: give notes and todos dedicated workspace layouts

Replace the crowded note sidebar with a card overview and full note detail. Keep tasks in a stable split view with source content and AI comments, compact header navigation, and search-adjacent status filters. Preserve drafts and return context.

Validation: 93 focused tests, typecheck, lint, and isolated Electron renderer checks passed. Full suite was interrupted; renderer probes used in-memory APIs.

Release note: Notes now open from a card overview, while todos keep a stable task list beside their details. Compact view and filter controls leave more room for reading and editing.

docs/features/magic-notes/progress.md

@@ -1,5 +1,70 @@
 # Magic Notes Progress
 
+## 2026-09-18: Stable Todo Split View and Header Navigation
+
+- Supersedes the inline task expansion described in the earlier entry below.
+  Wide containers now keep the grouped task list on the left and instructions,
+  source and AI in one right detail pane. Narrow containers retain the mounted
+  list and offer on-demand detail with an explicit return. Source-note return
+  preserves task context. Header tabs precede New note; filters follow search.
+- Focused workspace, editor and shared-primitives suites passed all 93 tests.
+  `npm run typecheck` and targeted ESLint passed. No full `npm test` was run.
+- Reused the temporary Electron renderer probe at 1280x820, 600x760,
+  600x520 dark and 420x640. The 134x36 header switch precedes New note at all
+  four sizes. Search/filter share a row at 1280 and 600; filters wrap at 420.
+  The wide list's width, top, scroll and adjacent row coordinates remain equal
+  before and after task selection/switching. Narrow returns preserve nonzero
+  list scroll and restore focus. No horizontal overflow or console errors.
+- Also verified source-note round trips at all sizes, actual Quill draft
+  confirmation, note-card return, AI visibility, task completion/status filters,
+  AI fixture results, creation and Chromium keyboard activation.
+- Visible-window capture initially failed with Electron `UnknownVizError`.
+  Final probe uses Electron offscreen rendering at scale 1, pointer input and
+  Chromium DevTools keyboard input. It runs production React/Quill/CSS with
+  in-memory API fixtures, not the full App/Main/SQLite/model path. Model calls: 0.
+  Evidence remains under the temporary `opencode` directory in
+  `magic-notes-render-results.json` and `magic-todos-*-expanded.png`.
+
+## 2026-09-18: Independent Todo Task View
+
+- Replaced todo full-page navigation with a grouped task list and one inline
+  expansion for instructions, source content and AI comments. Completion works
+  directly in each row. Search/status controls stay above the scrolling list;
+  source-note navigation retains expansion, filters and initiating focus.
+- Kept the note-card overview and note editor/AI layout. Notes/To-dos PageTabs
+  now size to their contents at desktop and narrow widths. Source failures offer
+  an inline retry alongside the existing notification.
+- Focused command: `npx vitest run src/renderer/src/MagicNotesWorkspace.test.tsx src/renderer/src/MagicNoteEditor.test.tsx src/renderer/src/WorkspacePrimitives.test.tsx`:
+  93 tests passed. `npm run typecheck` and ESLint on the workspace, its tests and
+  both changed locale modules passed. Full `npm test` was not rerun, as requested.
+- Reused the isolated Electron renderer probe at requested content sizes
+  1280x820, 600x760, 600x520 (dark) and 420x640. All four todo views retained
+  18 tasks, inline expansion, independently scrolling lists and no horizontal
+  overflow or detail/AI sidebar. Tabs measured approximately 133x35 CSS pixels.
+  Note-card navigation, actual Quill draft confirmation, AI visibility, source
+  navigation, direct completion, status filters and inline AI fixture output passed;
+  the renderer reported no console errors.
+- The probe uses production React, Quill and CSS with in-memory API fixtures and
+  isolated Electron sessions; it does not validate Main/SQLite or a live model.
+  Model calls: 0. Scripts, screenshots and JSON results remain in the existing
+  temporary `opencode/magic-notes-render-*` probe location.
+
+## 2026-09-18: Card Overview and Detail Navigation
+
+- Replaced the persistent inner list with a responsive card overview and explicit
+  detail navigation. Search, todo filters, overview scroll and initiating focus
+  survive a round trip. Creation opens the new note; todo source navigation returns
+  to the todo overview. Back navigation protects entry and title drafts.
+- Kept AI visibility and resizing preferences, removed obsolete list resizing,
+  and capped stacked AI height so short windows retain usable editor space.
+- Focused workspace, editor and shared UI suites passed 90 tests. Typecheck and
+  full lint passed. The first full test invocation exceeded its 200-second limit.
+- Isolated Electron rendering exercised the actual workspace, Quill and CSS at
+  1280x820, 600x760, 600x520 (dark), and 420x640. Navigation, creation, todo-source
+  jumps, draft confirmation, AI visibility, scroll and focus restoration passed.
+  These checks used in-memory API fixtures, not Main/SQLite integration; no real
+  model calls were made. Canvas functionality is outside this layout change.
+
 ## 2026-09-17: Note List Action Menu
 
 - Moved pin/unpin and whole-note deletion from the editor header to each note's