Repository source: docs/plans/offline_reading_release1/offline_reading_release1_step2_feature_description.md

Offline Reading Release 1 Step 2 Feature Description

Problem

Recent public discussion is unavailable when a visitor loses connectivity, even though the browser can already execute SQLite queries locally. The site needs a small, refreshable offline reading experience without exposing the complete operational read model or changing online writes.

User Stories

As a returning visitor, I want to browse the recent thread list offline so that I can catch up without a connection.
As a returning visitor, I want to open a recent thread and read all of its visible replies offline so that a listing is useful rather than a dead end.
As a visitor, I want to see when my offline content was last refreshed so that I understand it may be stale.
As an operator, I want offline content limited to intentionally public fields so that browser caching does not expose operational or private data.

Core Requirements

Cache a public-only snapshot of the 50 most recently active visible threads, every visible reply in those threads, and necessary display metadata; enforce a defined storage budget.
Make the snapshot available through an offline recent-thread reader after one successful online load; preserve the last complete snapshot while a refresh is pending or fails.
Clearly label offline and cached content with its snapshot generation time.
Keep posts, replies, reactions, APIs, account/tools pages, personalized pages, and the full read_model.sqlite3 online-only and outside the offline cache.
Preserve normal online navigation and graceful non-PWA behavior.

Shared Component Inventory

templates/layout.php / TemplateRenderer: extend the canonical shared layout for PWA discovery and registration; do not fork page chrome.
/threads/ board and /threads/{id} thread pages: reuse their public content semantics as the canonical online reader; add a new, deliberately narrow offline reader because server-rendered pages cannot query a local snapshot.
/tools/sqlite/ and sqlite_viewer.js: reuse the existing browser-local SQLite capability and runtime loading behavior; do not reuse its developer-query UI as the reader.
sql-wasm.js / sql-wasm.wasm: reuse as the local read-only query runtime.
Static artifact release and fingerprinted assets: extend the existing public-release/asset model for cacheable offline resources.
Compose, signing, and reaction surfaces: leave unchanged and online-only in this release.

User Flow

Visitor opens the public site online; the app shell and current recent-content snapshot become available locally.
Later, without a connection, the visitor opens the offline reader and sees the snapshot timestamp and recent thread list.
The visitor opens any listed thread and reads its visible replies locally.
On a later online visit, the app replaces the snapshot only after the new one is complete.

Success Criteria

After one successful online load, a browser in offline mode can open the offline reader, see a labeled recent-thread list, and read all visible replies in each of the snapshot's 50 threads.
The reader makes no network request while offline and still renders with its required local assets.
The cached artifact contains no workflow, LLM, handoff, account, session, or other non-public operational data.
A failed refresh leaves the previous complete snapshot readable; a successful refresh displays the new generation time.
Existing online reads and all write paths continue to work without service-worker support.