Test context hook error behavior

[ngan]

Summary

• Add integration tests verifying RSpec context hook error behavior for fixture_kit
• Confirms after(:context) (our finish hook) still runs when before(:context) (generate) raises
• Confirms examples execute normally before an after(:context) error is reported

Test plan

• after(:context) runs even when before(:context) raises — FKIT_ASSERT:AFTER_CONTEXT_RUNS_AFTER_BEFORE_ERROR marker emitted
• Examples pass before after(:context) error — FKIT_ASSERT:EXAMPLES_PASS_BEFORE_AFTER_ERROR marker emitted
• Both intentional errors appear in subprocess output
• Full suite passes (158 examples, 0 failures)

🤖 Generated with Claude Code