feat: Enable capture of profiling data (#290)

* feat: Enable capture of profiling data

Adding a new set of commands:
```
agent-browser profiler start

agent-browser profiler stop trace.json
```

With this, agents can start a profiling trace, perform a set of actions, and then extract the profiling data for analysis.

**Note:** I was originally going to call it `agent-browser profile` but I realized that might cause confusion with the `--profile` flag

CDP supports a couple commands for starting/stopping a trace.
When a trace is running, it emits events that need to be picked up.
We store these locally in the daemon until the trace is completed.
When the final event is received, we dump all of them into an output file.

That file can be loaded directly into chrome devtools or another analysis tool to visualize what happened during the agentic run.

Added some basic rust tests for parsing the commands (since they have some optional / required args)

TS daemon adds ~6 tests to make sure the profiling lifecycle (including saving the output file) works as intended

* add docs

* fixes

* fixes

---------

Co-authored-by: Chris Tate <chris@ctate.dev>

README.md

@@ -258,6 +258,8 @@ agent-browser dialog dismiss          # Dismiss
 ```bash
 agent-browser trace start [path]      # Start recording trace
 agent-browser trace stop [path]       # Stop and save trace
+agent-browser profiler start          # Start Chrome DevTools profiling
+agent-browser profiler stop [path]    # Stop and save profile (.json)
 agent-browser console                 # View console messages (log, error, warn, info)
 agent-browser console --clear         # Clear console
 agent-browser errors                  # View page errors (uncaught JavaScript exceptions)