[Pepps233]

Summary

Adds durable trace persistence for persisted coding-agent CLI invocations, covering session replacements, operation segments, harness activations, diagnostics, and shutdown outcomes.

Keeps ephemeral invocations untraced and treats recorder failures as passive so telemetry cannot block normal CLI behavior.

Reasoning

Invocation telemetry already exists in memory, but process and session replacement boundaries were not persisted.
The composition root now owns one recorder, while session runtimes report lifecycle facts through passive hooks.

Changes

• Adds immutable coding-agent session cursors and lifecycle observer hooks.
• Attaches session replacements, harness activations, operation segments, diagnostics, and termination status.
• Defines trace storage permissions and retention behavior.
• Vendors the private trace runtime into coding-agent release artifacts.
• Adds process-level coverage for startup, resume, replacement, ephemeral commands, signals, and recorder failures.

Testing

• npm run check
• ./test.sh
• node ../../node_modules/vitest/dist/cli.js --run test/invocation-tracing.test.ts test/suite/agent-session-harness-version.test.ts test/session-manager-trace-cursor.test.ts