Add incremental pyright type checking with CI enforcement

Add pyrightconfig.json with basic type checking for zero-error modules
(clocks, metrics, transcriptions, frames) and enforce via CI. The
include list will expand as modules are fixed.

pyrightconfig.json

@@ -0,0 +1,16 @@
+{
+  "typeCheckingMode": "basic",
+  "pythonVersion": "3.11",
+  "pythonPlatform": "All",
+  "include": [
+    "src/pipecat/clocks",
+    "src/pipecat/metrics",
+    "src/pipecat/transcriptions",
+    "src/pipecat/frames"
+  ],
+  "exclude": [
+    "**/*_pb2.py",
+    "**/__pycache__"
+  ],
+  "reportMissingImports": false
+}