* keep base path in logout redirect
* store manual event sub labels as verified objects
Manual events created with a sub label were stored in the review item as "label: sub_label", so review previews and collapsed History cards showed a generic icon, the review label filter missed them, and the sub label never reached sub_labels for chips, notifications, or GenAI prompts. The object processor now publishes the label and sub label separately, and the review maintainer stores them as label-verified plus a sub_labels entry, the same as tracked objects.
* only expire snapshots for events that still have one
Snapshot expiry selected every event older than snapshot retention, including events whose snapshot was already deleted, so with snapshot retention shorter than alert/detection retention the same missing files were unlinked again every cleanup cycle until the event row expired. That was nearly free on local disk but caused constant metadata load on network shares. The expiry queries now filter on has_snapshot so each snapshot is deleted once.
* keep frame shm open and skip overwritten frames
Every reader closed and reopened a frame's shared memory segment on each frame, so each process paid a page fault on every page of a fresh mapping (about 760 for a 1080p frame) per frame. Readers now keep segments mapped. Capture stamps each slot's frame time in a per-camera `{camera}_frame_times` segment, and `get()` returns None when the slot no longer holds the requested frame, reopening once by name so a mapping left over from a same-size camera recreate heals itself. Capture also reuses a slot when the frame queue is full, since no reader was told about it.
* verify the frame for embeddings object updates
Tracked object events only carried the object's own frame_time, which stays at its last detection when the object isn't detected in a frame, so embeddings couldn't check the slot it read and could crop face or plate data from a frame that had already been overwritten. Events now carry the time of the frame they name, and embeddings passes it to `get()`.
* log when a frame slot was overwritten before it was read
A lapped read and a missing segment ended up as the same debug line at every caller, so there was no way to tell a slow reader from a missing frame.
* bring the FrameManager interface in line with its implementation
The abstract get() still had a timeout_ms signature from an older implementation and frame_times() wasn't declared, though capture and detect are typed against the interface. get() also didn't say how long the array it returns stays valid.
* drop a camera's cached frame mappings when it is removed or recreated
A reader that kept its mappings open stayed on a removed camera's segments, which pinned their shared memory until restart, and after a same-size recreate the ledger reopen only refreshed the slot being read while the other cached slots still returned the old camera's pixels. Readers now drop every cached slot for a camera on its remove update, and get() does the same when a ledger mismatch turns out to be a replaced ledger rather than a lapped slot.
* match a camera's frame names exactly in close_camera
The prefix match on `{camera}_frame` also caught another camera whose name starts with it, so removing `cam` dropped the cached ring of a camera named `cam_frame`.
