Introduce ephemeral `workflow._auto_chain_active` flag to separate chain
propagation from the user's persistent `workflow.auto_advance` preference.
Previously, `workflow.auto_advance` was set to true by --auto chains and
only cleared at milestone completion. If a chain was interrupted (context
limit, crash, user abort), the flag persisted in .planning/config.json
and caused all subsequent manual invocations to auto-advance unexpectedly.
The fix adds a "sync chain flag with intent" step to discuss-phase,
plan-phase, and execute-phase workflows: when --auto is NOT in arguments,
the ephemeral _auto_chain_active flag is cleared. The persistent
auto_advance setting (from /gsd:settings) is never touched, preserving
the user's deliberate preference.
Closes#857
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
609f7f3ede