f1-stream: subreddit extractor finds Reddit '[Watch / Download]' threads

Two fixes for the previously-dormant subreddit extractor + a chrome-browser TARGETS pivot to MotoGP weekend live URLs.

1. **Reddit fetch was 403'd by `Accept: application/json`**. Cluster IP +
   that header trips Reddit's anti-bot fingerprint and returns HTML 403.
   Removing the explicit Accept (default `*/*`) restores HTTP 200 with
   JSON. Confirmed via direct httpx test from the f1-stream pod.

2. **Search the right things**. The community uses a stable
   `[Watch / Download] <Series> <Year> - <Round> | <Event>` post pattern
   with selftext links to admin-curated WordPress sites (motomundo.net
   for MotoGP, sister sites for F1 when active). New extractor:
   - Hits both /new.json and /search.json across r/MotorsportsReplays
     and three smaller motorsport subs.
   - Filters posts where title contains `[watch`, `watch online`, or
     flair = `live`.
   - Extracts URLs from selftext (regex), filters to a positive
     `_INTERESTING_HOSTS` allowlist (motomundo, freemotorsports,
     pitsport, rerace, dd12, etc.) so we don't drown the verifier in
     YouTube/Discord/gofile links.
   - Returns each as embed-type so the chrome-service verifier visits.

3. **chrome_browser.TARGETS pivoted** to the live MotoMundo MotoGP
   French GP iframes (motomundo.top/e/<id> + motomundo.upns.xyz/#<id>)
   while the weekend is on. The previous DD12 NASCAR + Acestrlms F1
   targets were both broken JW Player paths anyway.

State after deploy:
- /streams: 3 verified live (WRC Rally Portugal, NASCAR 24/7, Premier League Darts) — Darts is currently active because UK is mid-match.
- Subreddit extractor surfaces the live MotoMundo URL but the verifier
  marks the WordPress wrapper page playable=False (no top-level <video>
  element; the m3u8 lives in nested iframes). Next iteration: drill the
  verifier into iframe contentDocument and capture from there.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

stacks/f1-stream/files/backend/extractors/chrome_browser.py

@@ -51,23 +51,22 @@ class _Target:
 # whose m3u8 is JS-computed. Add freely — each one takes ~12s to scrape.
 # ---------------------------------------------------------------------------
 TARGETS: tuple[_Target, ...] = (
-    # DD12streams' /nas iframe → /new-nas/jwplayer → JW player setup with
-    # an inline m3u8. The HTML is generated server-side and the URL string
-    # is embedded directly, so this would also work over curl — but the
-    # browser path future-proofs against dd12 starting to compute the URL
-    # in JS.
+    # MotoMundo embed pages — the community-curated WordPress site for
+    # MotoGP. Each /e/<id> URL is one of the iframes their "Watch Online"
+    # post lists for the active session (FP/Q/Race). The m3u8 is
+    # JS-computed at load time so a real browser is required to capture
+    # it. Update IDs each weekend to match the current race; subreddit.py
+    # discovers them from the Reddit "[Watch / Download]" thread.
     _Target(
-        label="DD12Streams",
-        title="NASCAR Cup (24/7) — DD12",
-        url="https://dd12streams.com/nas",
-        settle=10,
+        label="MotoMundo",
+        title="MotoGP Live (MotoMundo) — French GP / Le Mans",
+        url="https://motomundo.top/e/9yzn08jk9py4",
+        settle=15,
     ),
-    # Acestrlms aggregator — always-on F1 page that re-frames pooembed.
-    # Captured m3u8 only appears once the embed's JS runs.
     _Target(
-        label="Acestrlms",
-        title="Sky Sports F1 (24/7) — Acestrlms",
-        url="https://acestrlms.pages.dev/f11/",
+        label="MotoMundo",
+        title="MotoGP Live (MotoMundo upns) — French GP / Le Mans",
+        url="https://motomundo.upns.xyz/#kqasde",
         settle=15,
     ),
 )