fix(runtime): preserve agent session capture during quit

[forketyfork]

Issue

When quitting Architect with multiple active agent sessions, some Claude resume IDs were not captured. The shutdown path could mark sessions as dead before draining all trailing PTY output, so late claude --resume <uuid> lines were sometimes missed.

Issue linkage is not included for this hotfix-path change; linkage will be added during mandatory cleanup.

Solution

This change keeps PTY output processing enabled for spawned sessions even after process exit, so late bytes can still flow into quit capture.

It also adds a bounded post-worker drain-until-quiet pass before UUID extraction. That extra drain window captures trailing shutdown output without making quit unbounded.

Finally, it removes raw terminal-tail debug logging that emitted control-heavy text into the launcher shell and made debugging noisy.

Test plan

• Start Architect with multiple terminals running Claude sessions that already have real conversation history.
• Quit Architect while those sessions are active and verify shutdown completes without control-sequence bleed into the launcher shell.
• Relaunch Architect and confirm previously active sessions resume from captured IDs instead of starting fresh.

[chatgpt-codex-connector]

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[Copilot]

Pull request overview

This PR fixes a shutdown edge case where agent resume UUIDs could be missed during quit by continuing to drain PTY output after process exit and performing a bounded “drain-until-quiet” pass before UUID extraction.

Changes:

• Keep SessionState.processOutput() active for spawned sessions even when marked dead, allowing post-exit PTY bytes to be processed/captured.
• Add a bounded post-worker quit-capture drain loop (poll + quiet-window + max-window) before extracting UUIDs.
• Remove noisy “terminal tail” debug logging during quit teardown and update the architecture ADR to reflect the new drain behavior.

Reviewed changes

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

File	Description
src/session/state.zig	Adjusts output-drain gating so quit capture can continue after session exit; adds a small unit test for the gating helper.
src/app/runtime.zig	Adds bounded post-worker output draining before UUID extraction; removes control-heavy debug tail logging; adds unit tests for drain stopping conditions.
docs/ARCHITECTURE.md	Updates ADR-014 to document post-exit drain behavior and the bounded drain-until-quiet pass.

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