feat(ombi): Add Ombi PALDRA integration for request management

- Add OmbiRetriever extending ArrRetriever for PALDRA compliance
- Add OmbiClient for low-level Ombi API communication
- Add getOmbiInstances() to config.js following multi-instance pattern
- Register Ombi in PALDRA registry with Ombi-specific methods
- Add external ID matching (TMDB/TVDB/IMDB) to Ombi requests
- Update DownloadMatcher to be async and enrich downloads with Ombi links
- Add getOmbiLink/getOmbiSearchLink helpers to DownloadAssembler
- Implement new service icon layout (Ombi + Sonarr/Radarr icons)
- Add CSS styling for service icons
- Update dashboard routes to include Ombi configuration
- Extend OpenAPI with Ombi tag and NormalizedDownload properties
- Update documentation (README, ARCHITECTURE, SECURITY, CHANGELOG)
- Add Ombi configuration to .env.sample

CHANGELOG.md

@@ -6,6 +6,34 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
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+## [1.8.0] - 2026-05-21
+
+### Added
+
+#### Ombi PALDRA Integration
+
+- **OmbiRetriever** — New PALDRA-compliant retriever extending `ArrRetriever`, registered in `arrRetrieverRegistry` alongside Sonarr/Radarr. Manages Ombi request data with 5-minute TTL cache and lookup maps by TMDB/TVDB/IMDB IDs.
+- **OmbiClient** — Low-level Ombi API client for HTTP communication (movie/TV requests, search by external ID, connection test).
+- **`getOmbiInstances()`** — New config function in `server/utils/config.js` following the existing multi-instance JSON array pattern; supports both `OMBI_INSTANCES` and legacy `OMBI_URL`/`OMBI_API_KEY` formats.
+- **PALDRA registry Ombi methods** — `getOmbiRetrievers()`, `getOmbiRequests()`, `getOmbiRequestsByType()`, `findOmbiRequest()` added to `arrRetrieverRegistry`.
+- **External ID matching** — Downloads are matched to Ombi requests using TVDB ID → TMDB ID (TV) and TMDB ID → IMDB ID (movies); falls back to an Ombi search link when no request exists.
+- **`getOmbiLink()` / `getOmbiSearchLink()`** — New helpers in `DownloadAssembler.js` following the `getSonarrLink`/`getRadarrLink` pattern.
+- **Service icon layout** — Downloads and history cards now render inline SVG icons (Ombi for all users; Sonarr/Radarr for admins) instead of linked series/movie names. CSS `.service-icons-container` and `.service-icon` classes added to `public/style.css`.
+- **OpenAPI** — `NormalizedDownload` schema extended with `ombiLink`, `ombiRequestId`, `ombiTooltip` nullable string properties; `Ombi` tag added to the spec.
+- **`OMBI_INSTANCES` / `OMBI_URL` / `OMBI_API_KEY`** — New environment variables documented in `.env.sample`, `README.md`, `ARCHITECTURE.md`, and `SECURITY.md`.
+
+### Changed
+
+- **`DownloadMatcher.js`** — `matchSabSlots`, `matchSabHistory`, and `matchTorrents` are now `async`; each matched download object is enriched with `ombiLink`, `ombiRequestId`, and `ombiTooltip` via `addOmbiMatching()`.
+- **`DownloadBuilder.js`** — `buildUserDownloads` accepts `ombiRetriever` and `ombiBaseUrl` in its options object and passes them through to matching context.
+- **Dashboard routes** — Both the REST endpoint and SSE stream now resolve the Ombi retriever from the PALDRA registry and include it in the download-building context.
+- **`arrRetrievers.js`** — PALDRA registry now imports `OmbiRetriever`, maps `'ombi'` in `retrieverClasses`, and initialises instances from `getOmbiInstances()`.
+- **`ARCHITECTURE.md`** — PALDRA section updated with OmbiRetriever description, registry API additions, and directory-structure entries. Technology stack table updated.
+- **`SECURITY.md`** — Threat model extended with Ombi API key exposure and rate-limit exhaustion mitigations.
+- **`README.md`** — Prerequisites and new *Ombi Integration (Optional)* configuration section added.
+
+---
+
 ## [1.7.1] - 2026-05-21
 
 ### Added