fix: guard active_user_messages/active_output_tokens in _build_completed_summary (#992)

[microsasa]

Closes #992

Problem

In _build_completed_summary, active_model_calls has an explicit if resume.session_resumed else 0 guard, but active_user_messages and active_output_tokens rely on an implicit invariant — that _first_pass never increments these counters without also setting session_resumed=True. A future refactor could break this invariant, causing double-counted tokens, spurious "↳ Since last shutdown" rows, and incorrect has_active_period_stats() results.

Fix

Apply the same guard consistently to all three active-period counters:

active_user_messages=(
    resume.post_shutdown_user_messages if resume.session_resumed else 0
),
active_output_tokens=(
    resume.post_shutdown_output_tokens if resume.session_resumed else 0
),

This is a no-op for current code paths but makes the contract explicit and self-documenting.

Testing

Added test_completed_session_zeroes_active_counters_despite_post_shutdown_values to TestResumeDetectionDirect — constructs a synthetic _ResumeInfo with session_resumed=False but non-zero post-shutdown counters and verifies the built summary zeros them out. Without the fix, this test fails.

Generated by Issue Implementer · ● 6.1M · ◷

[Copilot]

Pull request overview

This PR makes _build_completed_summary explicitly zero out all active-period counters (active_model_calls, active_user_messages, active_output_tokens) when resume.session_resumed is False, preventing future regressions from implicit invariants in _first_pass.

Changes:

• Add explicit resume.session_resumed guards for active_user_messages and active_output_tokens in _build_completed_summary.
• Add a direct regression test that constructs a synthetic _ResumeInfo with session_resumed=False but non-zero post-shutdown counters and verifies the summary zeros them out.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
src/copilot_usage/parser.py	Ensures active-period counters are consistently gated on session_resumed for completed sessions.
tests/copilot_usage/test_parser.py	Adds a regression test to enforce the contract that active counters must be zero when session_resumed=False.

[github-actions]

Low-impact defensive consistency fix with a targeted regression test. The production change adds if resume.session_resumed else 0 guards to active_user_messages and active_output_tokens — matching the existing guard on active_model_calls. No behavior change for current code paths. Test correctly exercises the invariant-violation scenario. All CI green. Auto-approving for merge.