* feat(app): show atomic document loading progress
- Preserve the existing full-canvas pencil loader while adding phase, detail, accessible status, and honest determinate progress
- Keep one generation-safe load owner across FIG decoding, graph preparation, page population, fonts, fallbacks, layout, viewport fitting, and first-render fade
- Prevent nested page setup and viewport cleanup from revealing partially prepared documents
- Cover obsolete sessions, font-resolution ownership, and staged loader UI
* refactor(app): scope editor preparation per tab
- Replace the shared loading boolean with one reactive preparation snapshot and one imperative controller per editor store
- Keep Core page work progress-only and inject canvas suspension from the app boundary
- Route FIG, storage, recovery, DOM import, and page switching through reusable tab-local preparation handles
- Abort only the closing tab's operation and cover generation safety, multi-tab isolation, progress UI, and disposal
* fix(editor): commit prepared pages atomically
- Prepare population, fonts, fallbacks, and layout without changing the visible page
- Reject cancelled and stale prepared pages before committing viewport, selection, and page events
- Keep the preparation overlay until the committed scene version is presented
- Cover call order, cancellation, stale generations, and presentation acknowledgement
* fix(app): stage imported documents before commit
- Prepare imported graphs in an isolated Core editor before replacing the live document
- Share font loading while keeping live selection, graph, renderers, and history untouched during staging
- Preserve the previous graph when staging is cancelled or fails and remove the duplicate pre-font layout pass
* refactor(app): namespace preparation UI
- Move canvas and tab preparation presentations into focused subfolders with concise component names
- Share progress and phase presentation helpers across preparation surfaces
- Show tab-local preparation status without covering the active canvas for background work
* fix(app): cancel preparation work at source
- Publish typed per-store preparation lifecycle events with explicit completion, cancellation, and failure outcomes
- Propagate tab-local AbortSignals through FIG parsing, population workers, and browser font downloads
- Keep cancellable font requests outside shared in-flight caches while retaining globally completed font registrations
- Stop FIG manifest previews from replacing the live graph before atomic document commit
* fix(app): cancel storage and DOM preparation
- Propagate preparation signals through S3 downloads, byte progress, local-cache boundaries, and DOM/CSS conversion checkpoints
- Reuse merged diagnostics and localized toasts for document, storage, and presentation failures
- Replace manual font concurrency and presentation timers with es-toolkit limitAsync and withTimeout
- Guard stalled first presentation and fix the merged recovery dialog title bindings
* fix(app): stage reload and font retry
- Prepare reload graphs in isolation and preserve the current document on read, decode, font, or layout failure
- Restore page and viewport state only after atomic graph commit with cancellable reload reads
- Run font Retry as a tab-local preparation with cache reset, final layout, picture invalidation, and presentation acknowledgement
- Keep completed document pixels visible while Retry reports activity in the tab
* fix(app): enforce exclusive preparation outcomes
- Complete document, storage, recovery, and DOM preparations only after successful commit
- Keep failed and cancelled handles terminal so lifecycle events cannot report contradictory outcomes
- Preserve external AbortError identity across storage timeouts and cancel streamed readers without returning partial bytes
- Cover credential-free pre-abort, mid-stream cancellation, progress cutoff, and terminal outcome exclusivity
* feat(diagnostics): record preparation outcomes
- Persist completed, cancelled, and failed preparation lifecycles through the validated diagnostics recorder
- Store only operation kind, outcome, cancellation or failure category, terminal phase, and coarse duration bucket
- Exclude document subjects, font families, storage identities, URLs, raw durations, messages, and stack traces
* chore(app): keep browser font tests with typography split
- Remove the browser font transport test inherited from a mixed cancellation commit; the source and coverage remain on the typography branch and safety snapshot
* test(vue): assert injected render suspension
- Exercise shouldSuspendRender instead of removed Core loading state\n- Preserve the contract that rendering resumes without a version change
* test(app): complete atomic preparation contracts
- Acknowledge first presentation in headless file-open tests\n- Assert the cancellable font-loading signature at the Tauri fallback boundary
* fix(app): preserve preparation cancellation
- Stage imported graphs before mutating live tabs and propagate aborts through page, DOM, font, and storage work\n- Use the accessible progress primitive and clamp determinate values\n- Cover fallback-font cancellation and yield pending-open test polling to the task queue
* test(text): await fallback font request cancellation
Start the mocked remote font request before aborting so the test proves that the active request receives the preparation signal.