`doInitLbug` unconditionally called `acquireInitLock`, which creates
`${dbPath}.init.lock` inside the workspace. On a Docker `:ro` bind
mount this fails with EROFS.
The init lock prevents a TOCTOU race during DB creation — read-only
opens never create databases and don't need it. Split the init path:
- Read-only: skip path cleanup, init lock, orphan sidecar removal,
and mkdir. Go straight to preflightLbugSidecars (allowQuarantine:
false) then openLbugConnection with readOnly: true.
- Writable: unchanged behavior (lock, cleanup, open).
- Shadow-replay recovery: catch EROFS/EACCES/EPERM from the writable
fallback in ensureReadOnlyConnectionUsable and surface an actionable
error instead of a raw filesystem exception.
Includes integration test verifying read-only open never creates
lbug.init.lock on disk.
Fixes#1783
Co-authored-by: Gergő Magyar <gergomagyar@icloud.com>
