Introduce `AnnotCtl.add_batch()` and `serve_rc_annots()` batch
handler to submit 1000s of gaps in single IPC msg instead of
per-annot round-trips. Server builds `GapAnnotations` from specs
and handles vectorized timestamp-to-index lookups.
Deats,
- add `'cmd': 'batch'` handler in `serve_rc_annots()`
- vectorized timestamp lookup via `np.searchsorted()` + masking
- build `gap_specs: list[dict]` from rect+arrow specs client-side
- create single `GapAnnotations` item for all gaps server-side
- handle `GapAnnotations.reposition()` in redraw handler
- add profiling to batch path for perf measurement
- support optional individual arrows for A/B comparison
Also,
- refactor `markup_gaps()` to collect specs + single batch call
- add `no_qt_updates()` context mgr for batch render ops
- add profiling to annotation teardown path
- add `GapAnnotations` case to `rm_annot()` match block
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
Gud Boi
d36de5910b