03: shared-logic sweep part 1 — process/exec lifecycle and output bounding #344

Part of #341.

What to build: bounded shared-logic sweep, part 1 — compare the private reference checkout's process/exec lifecycle handling and output bounding/truncation/preview logic against our packages/pyaos, packages/agent-core-v2, and CLI surfaces. Land only defects proven against our code, each with a regression test that fails before the fix. Every examined subsystem gets a private ledger row (adopted or not-applicable with ground), even when nothing lands.

Blocked by: #1 (sweep runs on the merged tree).

Status: ready-for-agent

• Comparison notes for both subsystems written to the private ledger with an adopt/not-applicable decision each
• Every landed fix has a focused test that fails at the pre-fix commit and passes after
• Touched packages' suites green (pyaos / agent-core-v2 / CLI as applicable)
• No brand, provenance, or non-English content added (leak gate clean)

Demo path: red-then-green evidence per fix (focused test run before and after).

Capability: deep/medium
Claims: exclusive: packages/pyaos/src/, packages/pyaos/test/, packages/agent-core-v2/src/features/