ML-197: add Elm-style Presto application

backlog/tasks/ml-197 - Provide-Elm-style-Presto-Music-Library-application.md

@@ -1,11 +1,11 @@
 ---
 id: ML-197
 title: Provide Elm-style Presto Music Library application
-status: In Progress
+status: Done
 assignee:
   - Codex
 created_date: "2026-05-26 05:39"
-updated_date: "2026-05-26 05:43"
+updated_date: "2026-05-26 05:56"
 labels:
   - presto
 dependencies: []
@@ -16,6 +16,13 @@ documentation:
   - presto/main.py
   - presto/tests/test_screens.py
   - presto/mise.toml
+modified_files:
+  - presto/music_library.py
+  - presto/tests/conftest.py
+  - presto/tests/test_screens.py
+  - presto/tests/test_music_library_architecture.py
+  - presto/mise.toml
+  - presto/README.md
 priority: medium
 ordinal: 30000
 ---
@@ -32,10 +39,10 @@ Add an alternative Presto Music Library application organized around the message
 
 <!-- AC:BEGIN -->
 
-- [ ] #1 A `music_library.py` application exposes the existing Home, calendar/day browsing, search, record detail, scrobble, network error, and display sleep interactions through the Elm-style runtime.
-- [ ] #2 Scrolling, cover loading, wake handling, and API request behavior remain consistent with the current Presto app constraints.
-- [ ] #3 Headless verification covers the new application screens and prevents accidental network access during render tests.
-- [ ] #4 User-facing or deployment documentation is updated if introducing the alternative application changes available usage or verification instructions.
+- [x] #1 A `music_library.py` application exposes the existing Home, calendar/day browsing, search, record detail, scrobble, network error, and display sleep interactions through the Elm-style runtime.
+- [x] #2 Scrolling, cover loading, wake handling, and API request behavior remain consistent with the current Presto app constraints.
+- [x] #3 Headless verification covers the new application screens and prevents accidental network access during render tests.
+- [x] #4 User-facing or deployment documentation is updated if introducing the alternative application changes available usage or verification instructions.
 <!-- AC:END -->
 
 ## Implementation Plan
@@ -60,4 +67,32 @@ Inspected `presto/poc.py`, `presto/main.py`, test harness, and `presto/mise.toml
 
 User approved the implementation plan on 2026-05-26 and requested that this task record be committed before application work begins.
 
+Implemented the standalone architecture-based entrypoint with `Model`/`Runtime`, message-driven transitions, command dispatch/effects, centralized rendering, prepared detail-cover effects, nonblocking drag messages, display sleep/wake consumption, API loading/reconnect effects, and scrobble feedback effects.
+
+Extended the emulator screen contract suite to cover both `main.py` and `music_library.py`, and added focused tests for the status state, render-without-cover-fetch, detail preparation messages, wake consumption, WiFi reconnect before search, and throttled drag updates.
+
+Added optional deployment documentation and a `music_library` mise deploy task. A compatible concurrent change switching the emulator task target to `music_library.py` was present in `presto/mise.toml`; it is not part of the agent-authored deploy-task hunk and will be left unstaged.
+
+Verified `main.py` and `music_library.py` with `py_compile` output directed to `/tmp`; verified the headless suite with `mise run test` (36 passed). Physical Presto hardware was not tested.
+
 <!-- SECTION:NOTES:END -->
+
+## Final Summary
+
+<!-- SECTION:FINAL_SUMMARY:BEGIN -->
+
+## Summary
+
+- Added `presto/music_library.py`, a standalone Music Library entrypoint organized around the Elm-style `Model` / `Runtime` / message / effect / render architecture while preserving the current UI and API interactions.
+- Routed blocking requests and detail-cover preparation through effects, retaining cached or placeholder-only redraw behavior during scroll interactions and wake/sleep handling.
+- Added deployment/documentation support and expanded emulator coverage to exercise both entrypoints plus the architecture-specific event/effect behavior.
+
+## Verification
+
+- `python3 -c "import py_compile; py_compile.compile('main.py', cfile='/tmp/main.pyc', doraise=True); py_compile.compile('music_library.py', cfile='/tmp/music_library.pyc', doraise=True)"`
+- `mise run test` (36 passed)
+
+## Remaining Validation
+
+- The architecture-based entrypoint has not been exercised on a physical Pimoroni Presto device.
+<!-- SECTION:FINAL_SUMMARY:END -->