This PR stabilizes the Nexus Ingestion Engine by implementing functional service proxies for the Blazor WASM client and refining the backend infrastructure for real-time progress tracking and database compatibility.
### Key Changes
- **Infrastructure Stabilization**:
- Implemented production-grade `EbookRepository` with PostgreSQL `EF.Functions.ILike` support.
- Enforced `IsReadyForReading = false` state for newly added ebooks (resolves#35).
- Updated `SignalRSyncBroadcaster` to support targeted user messaging and ingestion-specific progress updates (resolves#37).
- **WASM Client Functional Proxies**:
- Replaced "Throwing" dummy services with `WasmEbookRepository`, `WasmSyncBroadcaster`, `WasmBookStorageService`, and `WasmEmbeddingGenerator`.
- These services proxy requests to the backend via a new set of Minimal API endpoints in `NexusReader.Web`.
- **Domain Refinement**:
- Added `IsReadyForReading` flag to the `Ebook` entity to manage background AI processing states.
### Related Issues
- Fixes#35
- Fixes#36
- Fixes#37
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Co-authored-by: Marek Jasiński <jasins.marek@gmail.com>
Reviewed-on: #42
Co-authored-by: Antigravity <antigravity@google.com>
Co-committed-by: Antigravity <antigravity@google.com>
