feat: enable VP9/AV1 codecs at LiveKit SFU (Issue #11 test)

Appends video/VP9 and video/AV1 to the SFU's room.enabled_codecs
allow-list via matrixRTC.sfu.additional, keeping all currently
negotiated codecs unchanged. Opt-in test per Issue #11 - codecs
become selectable, not the new default.

apps/production/element-server-suite.yaml

@@ -74,6 +74,26 @@ spec:
           cpu: 50m
         limits:
           memory: 128Mi
+      sfu:
+        # Issue #11 test (2026-07-29): opt-in VP9/AV1 support. LiveKit's built-in
+        # default enabled_codecs list is [VP8, H264, H265, rtx, PCMU, PCMA, opus, red]
+        # (confirmed live via SFU negotiation logs) - VP9/AV1 appended, nothing removed,
+        # so the existing default path is unaffected either way.
+        additional:
+          0-codecs:
+            config: |
+              room:
+                enabled_codecs:
+                  - mime: video/VP8
+                  - mime: video/H264
+                  - mime: video/H265
+                  - mime: video/rtx
+                  - mime: audio/PCMU
+                  - mime: audio/PCMA
+                  - mime: audio/opus
+                  - mime: audio/red
+                  - mime: video/VP9
+                  - mime: video/AV1
 
     # Element Web
     elementWeb: