Changelog

LocalStorageProvider.StoreFileAsync was synchronous despite the async

signature — it called File.OpenRead + SHA256.HashData on the UI thread.

When the source file is on a cloud mount (Google Drive, iCloud), the

read can stall or timeout, throwing an IOException that propagated up

through the Avalonia dispatcher as an unhandled exception, killing the app.

Fixed by making StoreFileAsync truly async: file hashing now uses an

async FileStream with SHA256.ComputeHashAsync on a background thread,

with a 30-second timeout via linked CancellationTokenSource.

Desktop v1.66.4

Add photo section editor with file picker, layout selector (Full Width /

2 Column / 3 Column), and photo preview grid. Photos stored via

IStorageProvider (content-addressable dedup). PhotoSectionView displays

photos using AsyncImage with UniformGrid layout based on PhotoLayout.

Wire IStorageProvider resolution in JournalPlugin via capability broker,

passed to ViewModel for storage access. Add photo section to both Feed

and Focused view rendering.

The cloud sync was hitting 429 rate limits and not properly backing off,

causing repeated error spam. The C# refresh timer kept calling GetQuota()

every 15 seconds even during rate limits, generating cascading 429 errors.

Rust API client (api_client.rs):

• Added sliding window request counter that enforces 75% of the server's

advertised rate limit (450 req/60s instead of 600). Proactively throttles

before hitting the server limit.

• Changed 429 backoff to use 2x the server's Retry-After header with a

60-second floor. Previously used 1x which allowed immediate re-triggering.

• Counter limits are updated from server config on sync engine startup.

Rust FFI layer:

• Added PrivStackError::RateLimited (= 36) to distinguish rate limits from

generic CloudSyncError. Previously all rate limit errors mapped to

CloudSyncError and C# couldn't tell them apart.

• Rate limit errors now log as WARN instead of ERROR (expected transient).
• CloudSyncStatus now includes is_rate_limited and rate_limit_remaining_secs

fields, populated from the API client's gate state.

C# desktop:

• CloudSyncSettingsViewModel.RefreshStatusAsync() checks is_rate_limited

from status and skips all API calls (quota, devices, tokens) when true.

This eliminates the cascading 429 errors from the refresh timer.

• Catches PrivStackError.RateLimited specifically instead of falling through

to the generic exception handler.

• Status refresh timer slows from 15s to 30s during rate limit pause (still

updates the remaining-seconds display but doesn't hit the API).

• Added IsRateLimited and RateLimitDisplay observable properties for UI.

Rust v1.15.2, Desktop v1.66.3

• Add IsDetached property and RequestReattach command to AiSuggestionTrayViewModel
• Show reattach button (dock icon) in tab strip when tray is detached
• Add content margin (8px sides/bottom) to AiTrayWindow for breathing room
• Wire ReattachRequested event in MainWindow detach/reattach lifecycle
• Version bump 1.66.1 → 1.66.2