fix(cli): honor skip postprocess flags

[iamstuffed]

Summary

Fix the build and update CLI commands so their post-processing flags are honored.

Previously, the CLI passed the selected postprocess level into build_or_update_graph(...), but then ran the older full CLI post-processing pipeline afterward. As a result:

• code-review-graph build --skip-postprocess still ran full post-processing.
• code-review-graph update --skip-flows still ran flow/community post-processing.
• CLI output could report postprocess=none or postprocess=minimal while doing more work than requested.

This PR removes the extra CLI post-processing pass and relies on build_or_update_graph(...) as the source of truth for none, minimal, and full post-processing behavior.

Changes

• Remove the extra _cli_post_process(...) calls after build_or_update_graph(...).
• Remove the now-unused _cli_post_process helper.
• Add CLI regression coverage for:
  • build --skip-postprocess
  • update --skip-flows
• Add pytest-asyncio to the uv dev dependency group so uv run python -m pytest installs the async test plugin used by the existing test suite.

Validation

uv run python -m pytest

Result:

1238 passed, 1 skipped, 2 xpassed in 16.79s

[Copilot]

Pull request overview

This PR fixes CLI post-processing flag handling by removing the extra CLI-level post-processing pass and relying on build_or_update_graph(...) to enforce none, minimal, and full behavior.

Changes:

• Removed the unused _cli_post_process(...) helper and its calls from build/update.
• Added regression tests for build --skip-postprocess and update --skip-flows.
• Added pytest-asyncio to the uv dev dependency group.

Reviewed changes

Copilot reviewed 3 out of 4 changed files in this pull request and generated no comments.

File	Description
code_review_graph/cli.py	Stops running a second post-processing pass after build/update.
tests/test_cli.py	Adds CLI regression tests for skip post-processing behavior.
pyproject.toml	Adds pytest-asyncio to dependency groups for test execution via uv.
uv.lock	Updates locked dev dependency metadata for pytest-asyncio.