Adds internal/provlog with a single Event(name, fields) helper that
emits JSON-tagged single-line records to the standard logger. Five
boundary sites instrumented for #2867:
provision.start — workspace_dispatchers.go (sync + async)
provision.skip_existing — org_import.go idempotency hit
provision.ec2_started — cp_provisioner.go after RunInstances
provision.ec2_stopped — cp_provisioner.go after TerminateInstances ack
restart.pre_stop — workspace_restart.go before Stop dispatch
These pair with the existing human-prose log.Printf lines (kept). The
new records are grep+jq friendly so a future log-aggregation pipeline
can reconstruct per-workspace provision timelines without parsing the
operator messages — this is the "and debug loggers so it dont happen
again" half of the leak-prevention work.
Tests:
- provlog: emits evt-prefixed JSON, nil-tolerant, marshal-error
fallback preserves event boundary, single-line output pinned.
- handlers: provlog_emit_test.go pins three call-site contracts:
provisionWorkspaceAutoSync emits provision.start with sync=true,
stopForRestart emits restart.pre_stop with backend=cp on SaaS,
and backend=none when both backends are nil.
Field taxonomy is convenience for ops, not contract — payload can grow
additively without breaking callers. Behavior gate is the event name +
boundary location, per feedback_behavior_based_ast_gates.md.
Refs #2867 (PR-D structured logging at provisioning boundaries)
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>