fix: close TTY attribution review gaps

[azooz2003-bit]

Follow-up to merged PR #16559, addressing both cubic review findings.

• Keep cmux launch evidence rooted at the app PID, independent of each window's app_process_pids, so non-key and workspace-filtered windows retain shell attribution without charging the app itself to their resources.
• Expand process-group members only when the proven PID is still the live group leader, preventing PID-reuse attribution after a leader exits.
• Add runtime regression coverage for both paths.

Regression-first commits:

• b4e408f8ae2 adds the global launch-evidence and stale-group tests.
• d837e94cca2 applies the fixes.

Validation: ./scripts/sync-test-wiring --check, git diff --check.

— Cattail g1 🔸

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Summary by cubic

Fixes TTY attribution gaps left by the prior cubic-review follow-up: launch evidence is now rooted at the cmux app PID so shells in non-key or workspace-filtered windows retain attribution, and process-group members are only attributed while their proven leader is still the live group leader, preventing PID-reuse misattribution. Adds regression tests covering both paths.

^{Written for commit d837e94. Summary will update on new commits.}

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Migrated from #16619 after correcting the PR author identity. The original head commit d837e94 is preserved.

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📥 Commits

Reviewing files that changed from the base of the PR and between ccefb63 and d837e94.

📒 Files selected for processing (3)

• Sources/CmuxTopTTYOwnership.swift
• Sources/TerminalControllerTopSupport.swift
• cmuxTests/CmuxTopTTYCollisionAttributionTests.swift

• Autopilot · Keep fixing CodeRabbit findings and required CI, and resolving merge conflicts

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Note

Pull Request opener @azooz2003-bit is not an author or co-author of any commit in this PR (commit identities: teamleaderleo). The CLA check will still proceed and requires every listed identity plus @azooz2003-bit to have signed.

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