v0.34.1

Patch release fixing an upgrade lockout on Linux and adding a migration lane for downstream forks.

Fixes

Migration guard PID-reuse lockout (#281): v0.34.0's migration guard treated any RPC discovery record with an existing PID as a live OpenCode server. After OS PID reuse (common on Linux across reboots), a stale record could point at an unrelated process, blocking the pending migration and disabling the plugin fail-closed. The guard now verifies process identity (start time, with a command-name fallback for older records) before treating a record as live, and cleans up provably stale discovery files instead of letting them accumulate. Probe failures keep the guard's safe direction: uncertainty still blocks.
Mural config block (#278): experimental.mural graduated to a top-level mural block. Existing configs keep working via a legacy read fallback.
Verifiable dreamer progress (#272): /ctx-dream and status surfaces now report per-task progress signals instead of a bare running state.

Downstream migration lane (#280): context.db schema versions below 10000 are reserved for Magic Context; forks and sibling plugins sharing the database use 10000 and above. All version fences, probes, and displays now read only the upstream lane, and migration pendingness checks each candidate directly — a compliant fork's rows no longer trip the schema fence or silently skip upstream migrations. See docs/migration-version-lanes.md.