Add support for fetching and showing artist image & bio

Adds support for fetching and showing artist image & bio
from MusicBrainz, TMDB, and Wikidata, in case images are
not available, user can manually set an image via search
using those providers or an absolute image URL.

Author: kushalpandya

.swiftlint.yml

@@ -172,7 +172,7 @@ custom_rules:
   space_after_comment:
     included: ".*\\.swift"
     name: "Space After Comment"
-    regex: '(\/\/\w+)'
+    regex: '(?<!:)(\/\/\w+)'
     message: "Add a space after //"
     severity: warning
 

ACKNOWLEDGEMENTS.md

@@ -165,8 +165,38 @@ Individual codec library licenses can be found in their respective source reposi
 
 ---
 
+## Online Data Sources
+
+Petrichor fetches artist metadata from the following online services:
+
+### Artist Images
+
+- **MusicBrainz** - https://musicbrainz.org/
+  - Used to search for artist identifiers and Wikidata links
+  - Licensed under [CC0](https://creativecommons.org/publicdomain/zero/1.0/)
+
+- **Wikidata / Wikimedia Commons** - https://www.wikidata.org/
+  - Used to resolve artist images from Wikidata entities
+  - Licensed under [CC0](https://creativecommons.org/publicdomain/zero/1.0/)
+
+- **TMDB (The Movie Database)** - https://www.themoviedb.org/
+  - Used as a fallback source for artist images
+  - This product uses the TMDB API but is not endorsed or certified by TMDB
+
+### Artist Biographies
+
+- **Last.fm** - https://www.last.fm/
+  - Used to fetch artist biography summaries
+
+### Lyrics
+
+- **LRCLIB** - https://lrclib.net/
+  - Used to fetch song lyrics when not available locally
+
+---
+
 ## Acknowledgments
 
-Petrichor is grateful to all the open source projects and their contributors that make high-quality audio playback on macOS possible.
+Petrichor is grateful to all the open source projects, data sources, and their contributors that make this app possible.
 
-_Last Updated: November 2025_
+_Last Updated: March 2026_

Configuration/Info.plist

@@ -64,5 +64,9 @@
     <string>$(LASTFM_API_KEY)</string>
     <key>LASTFM_SHARED_SECRET</key>
     <string>$(LASTFM_SHARED_SECRET)</string>
+
+    <!--  TMDB  -->
+    <key>TMDB_READ_ACCESS_TOKEN</key>
+    <string>$(TMDB_READ_ACCESS_TOKEN)</string>
 </dict>
 </plist>

Configuration/Secrets.xcconfig.template

@@ -1,5 +1,9 @@
 // Last.fm API Credentials
 // Copy this file to Secrets.xcconfig and fill in your own values
 // Get your API key at: https://www.last.fm/api/account/create
-LASTFM_API_KEY = 
-LASTFM_SHARED_SECRET =
+LASTFM_API_KEY =
+LASTFM_SHARED_SECRET =
+
+// TMDB API Credentials
+// Get your token at: https://www.themoviedb.org/settings/api
+TMDB_READ_ACCESS_TOKEN =