fix(espn): send an identifying User-Agent so ESPN stops returning 403 (#436)

Around 11:00 EDT on 2026-08-04 ESPN's site.api began rejecting the agents
this repo sends. Every scoreboard that goes through the shared data
sources returned `403 Client Error: Forbidden` — standings, game
summaries and scoreboards alike. A device that had been running fine
logged 287 ESPN errors in a day.

The filter is not the familiar one. Probing site.api across agents and
libraries, using requests as the plugins do:

    bare 'LEDMatrix/1.0'                     403   (with or without Accept)
    browser string                           403   (no header rescues it)
    'LEDMatrix/1.0 (+https://github.com/...)' 200
    requests / urllib / curl defaults        200

So it rejects browser-style strings outright and bare custom tokens, and
accepts honest client tokens or an agent that identifies the client and
links to it. The instinct to "just send a browser User-Agent" is now
exactly backwards — that is the one thing guaranteed to stay blocked.

Both call sites here sent a bare token: `LEDMatrix/1.0` in the sports
data sources and `LEDMatrix-Common/1.0` in the API helper. The Accept
header the data sources already sent does not save it. Both now send an
agent carrying the project URL, which also gives ESPN someone to contact
rather than an anonymous token to rate-limit.

Verified on a live device: ESPN errors went from a steady stream to zero
across a restart, with live MLB games fetching again.


Claude-Session: https://claude.ai/code/session_01Udr6MfaFLUPhX5Fgo67Jf5

Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>

src/base_classes/data_sources.py

@@ -44,9 +44,16 @@ class DataSource(ABC):
         """Fetch standings for a sport/league."""
     
     def get_headers(self) -> Dict[str, str]:
-        """Get headers for API requests."""
+        """Get headers for API requests.
+
+        The agent carries the project URL deliberately. Around 2026-08-04 ESPN
+        began returning 403 for bare custom tokens like 'LEDMatrix/1.0' — and
+        for browser-style strings — while accepting an agent that identifies
+        the client and links to it. An Accept header alone does not rescue the
+        bare form when the request goes out through requests.
+        """
         return {
-            'User-Agent': 'LEDMatrix/1.0',
+            'User-Agent': 'LEDMatrix/1.0 (+https://github.com/ChuckBuilds/LEDMatrix)',
             'Accept': 'application/json'
         }
 

src/common/api_helper.py

@@ -56,7 +56,9 @@ class APIHelper:
         
         # Default headers
         self.session.headers.update({
-            'User-Agent': 'LEDMatrix-Common/1.0',
+            # Identifies the client and links to it: ESPN began 403ing bare
+            # custom tokens (and browser strings) around 2026-08-04.
+            'User-Agent': 'LEDMatrix/1.0 (+https://github.com/ChuckBuilds/LEDMatrix)',
             'Accept': 'application/json',
             'Accept-Language': 'en-US,en;q=0.9',
             'Accept-Encoding': 'gzip, deflate, br',