Follow-up to #18273 (not merged yet hence no changeset here): We can run
into a null-pointer when wanting to increment/decrement inside an effect
root that is outside a the component tree. Similarly, if not using the
component logic to unset context at the right time we gotta do it
"manually" inside `save`.

---------

Co-authored-by: Rich Harris <rich.harris@vercel.com>
Co-authored-by: vercel[bot] <35613825+vercel[bot]@users.noreply.github.com>

This PR was opened by the [Changesets
release](https://github.com/changesets/action) GitHub action. When
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yet, that's fine, whenever you add more changesets to main, this PR will
be updated.


# Releases
## svelte@5.55.10

### Patch Changes

- fix: unlink errored and otherwise finished batch
([#18264](#18264))

- perf: walk composedPath() directly in delegated event propagation
([#18268](#18268))

- fix: transfer effects when merging batches
([#18254](#18254))

- fix: allow `$derived(await ...)` in disconnected effect roots
([#18273](#18273))

- fix: remove temporary raw-text hydration markers
([#18269](#18269))

- fix: propagate async `@const` blockers through closure references so
template expressions like `{(() => host)()}` correctly wait for the
awaited value ([#18309](#18309))

- fix: properly unlink batches
([#18298](#18298))

- fix: settle discarded batch
([#18290](#18290))

- fix: declare `let:` directives before `{@const}` declarations on
slotted elements
([#18271](#18271))

- fix: resume outro-ed branches if they were kept around
([#18291](#18291))

- fix: avoid waterfall-warning when async resolves to same value
([#18297](#18297))

- fix: correctly coordinate component-level effects inside async blocks
([#18260](#18260))

- fix: make unnecessary commit work less likely
([#18263](#18263))

- chore: add tag name to `a11y_click_events_have_key_events` warning
([#18272](#18272))

- fix: catch rejected promises while merging/committing
([#18266](#18266))

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>