fix(logging): replace stdlib-style exc_info kwargs with loguru opt(exception=)

Loguru has no exc_info kwarg: extra kwargs are str.format() arguments, so
logger.error(f"...{e}", exc_info=True) forces .format() on the rendered
message — any error text containing braces (e.g. a JSON error body) raises
KeyError FROM the log call itself, escaping the surrounding except block and
killing the caller (observed: whole agent turns dying in benchmark runs).
The intended traceback was also never logged, since exc_info is not a loguru
feature.

Batch fix of all 143 sites across 11 files:
  logger.X(msg, exc_info=True) -> logger.opt(exception=True).X(msg)
  (one exc_info=exc site -> opt(exception=exc))
Messages are byte-identical; with the kwarg gone loguru never calls
.format(), so brace-containing f-string messages are inert.

Verified: AST post-conditions per file, py_compile, import smoke of all
modules, behavioral equivalence of the 3 patterns, full unit suite (1549
passed) with a failure set identical to the pristine tree (22 pre-existing,
zero regressions).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Also add pixel-agents to the README acknowledgements.

opc/plugins/office_ui/services/context.py

@@ -174,7 +174,7 @@ class OfficeServiceContext:
             try:
                 wire(engine)
             except Exception:
-                logger.debug("Failed to wire service project engine callbacks", exc_info=True)
+                logger.opt(exception=True).debug("Failed to wire service project engine callbacks")
         return engine
 
     async def activate_project(self, project_id: str) -> Any: