fix(cli): preserve Databricks profile shorthand (#5143)

## Related issue

[OMNI-4272](https://linear.app/omnigent/issue/OMNI-4272/add-a-global-profile-option-to-omni-cli-for-profiling)

## Summary

- Rename the global CPU profiler flag from `--profile` to `--profiling` so it no longer collides with the existing Databricks `--profile NAME` option.
- Preserve the historical bare-run shorthand `omni --profile my-sp ...` while keeping CPU profiling available for every explicit command.
- Add regression coverage for both options used independently and together.

**ELI5:** `--profiling` measures performance; `--profile NAME` continues to choose Databricks credentials.

```text
omni --profiling COMMAND       -> CPU profile
omni --profile my-sp -p "..."  -> run with Databricks profile my-sp
```

## Test Plan

- `uv run ruff format omnigent/cli.py tests/cli/test_cli.py`
- `uv run ruff check omnigent/cli.py tests/cli/test_cli.py`
- `uv run pytest -q tests/cli/test_cli.py::test_global_profiling_writes_summary_and_timestamped_stats tests/cli/test_cli.py::test_removed_ad_hoc_detection tests/cli/test_cli.py::test_help_groups_harnesses_and_other_commands tests/cli/test_cli.py::test_run_profile_sets_databricks_config_profile_env tests/cli/test_cli.py::test_bare_run_profile_shorthand_still_selects_databricks_profile tests/cli/test_cli.py::test_global_profiling_coexists_with_run_databricks_profile`

## Demo

N/A

## Type of change

- [x] Bug fix
- [ ] Feature
- [ ] UI / frontend change
- [ ] Refactor / chore
- [ ] Docs
- [ ] Test / CI
- [ ] Breaking change

## Test coverage

- [x] Unit tests added / updated
- [ ] Integration tests added / updated
- [ ] E2E tests added / updated
- [ ] Manual verification completed
- [ ] Existing tests cover this change
- [ ] Not applicable

## Coverage notes

The tests exercise the real module entry point for CPU profiling and `main()` argv rewriting for the historical Databricks profile shorthand.

## Changelog

Use `omni --profiling COMMAND` for CPU profiling without conflicting with Databricks `--profile NAME` selection.

Signed-off-by: Zeyi (Rice) Fan <zeyi.f@databricks.com>

omnigent/cli.py

@@ -1894,7 +1894,7 @@ def _extract_global_logging_flags(argv: list[str]) -> tuple[list[str], bool, boo
 
 @click.group(cls=_OmnigentCLI)
 @click.option(
-    "--profile",
+    "--profiling",
     is_flag=True,
     is_eager=True,
     expose_value=False,
@@ -2142,7 +2142,7 @@ def main() -> None:
             "--help",
             "-h",
             "--version",
-            "--profile",
+            "--profiling",
         }
     ):
         argv = ["run", *argv]
@@ -2316,7 +2316,7 @@ def _is_removed_ad_hoc_invocation(argv: list[str]) -> bool:
         return False
     # A root profiling flag may precede an eager help/version flag or stand
     # alone. These are valid Click invocations, not removed ad-hoc chat.
-    if all(token in {"--profile", "--help", "-h", "--version"} for token in argv):
+    if all(token in {"--profiling", "--help", "-h", "--version"} for token in argv):
         return False
     # Skip leading flags to find the first positional. If all
     # tokens are flags (e.g. ``omnigent --system-prompt "..."``),