Harden issue 10 reliability lifecycle and failure paths

[douglasjarquin]

Closes #10

Summary

• Add stable failure codes and durable terminal-state retry/fallback for capture, interruption, transcription, cleanup, cancellation, and insertion failures.
• Fence capture and transcription callbacks by operation UUID so late callbacks cannot mutate a newer session.
• Observe input-device, engine-configuration, sleep, and workspace-resign-active interruptions with idempotent recorder teardown.
• Await tracked child work during both ordinary and transcription shutdown paths.
• Add Swift SPI fault injection for disk, speech, cleanup timeout, target loss, and cancellation-race paths.
• Keep target loss copy-only and document host-limited hardware/live coverage as INCONCLUSIVE.

Validation

• Exact head: 217aef270875aeddafc9b89debb8f2230d68ddec.
• Exact live base: ca349411c45b9738983d6793bb2f7136a57faeba.
• DEVELOPER_DIR=/Applications/Xcode.app/Contents/Developer swift build passed.
• Spike and issue [02/13 · MVP] Build the native menu-bar shell and dictation state machine #3 through [09/13 · Reliability] Harden device changes, interruptions, cancellation, and failure paths #10 executable contract suites passed, including issue [09/13 · Reliability] Harden device changes, interruptions, cancellation, and failure paths #10 cleanup-timeout and transcription-shutdown-await scenarios.
• RED evidence recorded three behavioral failures before production edits in .ulw/evidence/issue10-red-bound-ce9d388.log; the exact-head issue [09/13 · Reliability] Harden device changes, interruptions, cancellation, and failure paths #10 suite is green.
• Native AppKit QA launched the real Oigo product, showed onboarding and the status menu, clicked Quit Oigo, and observed NSTerminateNow, clean termination, and no remaining process.
• Exact-head evidence: .ulw/evidence/full-regression.log, .ulw/evidence/issue10-native-qa.log, and .ulw/evidence/issue10-native-qa.png.
• Final delivery audit: .ulw/evidence/full-regression.log, .ulw/evidence/issue10-native-qa.log, and .ulw/evidence/debug-audit.log.
• LSP diagnostics are clean on all changed Swift and package files.
• Exact-SHA review: goal gate PASS, code review APPROVE with no high blockers, and security gate PASS; QA and context lanes are INCONCLUSIVE because they stayed silent across bounded waits.

Host limitations

Physical device switching, AirPods/USB unplug and reconnect, sleep/wake, lock/unlock, microphone permission revocation, external target termination, and live speech assets were unavailable in this host run and remain explicitly INCONCLUSIVE in the reliability matrix.

No merge or issue close is included in this change.