fix: prevent fatal oo-editors write EPIPE crashes

[interpreterwork]

Summary

• treat stdout/stderr EPIPE as expected stream-closure shutdown instead of fatal process crash
• stop writing logs to a stream once that stream is known broken to prevent recursive write EPIPE loops
• keep non-EPIPE stdio errors as fatal (exitCode=1) and continue reporting them through Sentry lifecycle hooks

Repro and Verification

Repro before fix

(FONT_DATA_DIR=/tmp/oo-fontdata PORT=39231 node oo-editors/server.js | head -n 1)

• exit status: 1
• output included repeated uncaught exception: Error: write EPIPE

After fix

Same command:

• exit status: 0
• output: startup line only, no uncaught write EPIPE

Unit tests

• pnpm --dir oo-editors --ignore-workspace run test:unit (pass)