Change mentions of 0-day to same-day (#22763)

There's some discussion in the community of the best way to describe
this, but 0-day has associations with vulnerabilities. "Same-day
support" seems to the currently agreed upon phrase other products use.

# Checklist for submitter

If some of the following don't apply, delete the relevant line.

<!-- Note that API documentation changes are now addressed by the
product design team. -->

- [ ] Changes file added for user-visible changes in `changes/`,
`orbit/changes/` or `ee/fleetd-chrome/changes`.
See [Changes
files](https://github.com/fleetdm/fleet/blob/main/docs/Contributing/Committing-Changes.md#changes-files)
for more information.
- [ ] Input data is properly validated, `SELECT *` is avoided, SQL
injection is prevented (using placeholders for values in statements)
- [ ] Added support on fleet's osquery simulator `cmd/osquery-perf` for
new osquery data ingestion features.
- [ ] Added/updated tests
- [ ] If paths of existing endpoints are modified without backwards
compatibility, checked the frontend/CLI for any necessary changes
- [ ] If database migrations are included, checked table schema to
confirm autoupdate
- For database migrations:
- [ ] Checked schema for all modified table for columns that will
auto-update timestamps during migration.
- [ ] Confirmed that updating the timestamps is acceptable, and will not
cause unwanted side effects.
- [ ] Ensured the correct collation is explicitly set for character
columns (`COLLATE utf8mb4_unicode_ci`).
- [ ] Manual QA for all new/changed functionality
- For Orbit and Fleet Desktop changes:
- [ ] Orbit runs on macOS, Linux and Windows. Check if the orbit
feature/bugfix should only apply to one platform (`runtime.GOOS`).
- [ ] Manual QA must be performed in the three main OSs, macOS, Windows
and Linux.
- [ ] Auto-update manual QA, from released version of component to new
version (see [tools/tuf/test](../tools/tuf/test/README.md)).

handbook/engineering/README.md

@@ -545,16 +545,16 @@ Once the Digital Experience department approves inventory to be shipped from Fle
 7. Add a comment to the equipment request issue, at-mentioning the requestor with the FedEx tracking info and close the issue.
 
 
-### Provide 0-day support for major version macOS releases
+### Provide same-day support for major version macOS releases
 
-Beginning with macOS 16, Fleet will offer 0-day support for all major version macOS releases. 
+Beginning with macOS 16, Fleet will offer same-day support for all major version macOS releases. 
 
 1. Install major version macOS beta release on test devices. 
 2. Create a new [QA release issue](https://github.com/fleetdm/fleet/issues/new?assignees=xpkoala%2Cpezhub&labels=%23g-mdm%2C%23g-endpoint-ops%2C%3Arelease&projects=&template=release-qa.md&title=Release+QA%3A+macOS+16) with the new major version in the issue title.
 3. Complete all manual smoke tests in the issue and confirm they are passing. 
 4. Confirm all automated tests are passing.
 5. [File bugs](https://github.com/fleetdm/fleet/issues/new?assignees=&labels=P1%2Cbug%2C%3Areproduce%2C%3Aincoming&projects=&template=bug-report.md&title=) with a `P1` label and assign to the appropriate [product group](https://fleetdm.com/handbook/company/product-groups#current-product-groups).
-6. When all bugs are fixed, follow the [writing a feature guide](https://fleetdm.com/handbook/engineering#write-a-feature-guide) process to publish an article announcing Fleet 0-day support for the new major release.
+6. When all bugs are fixed, follow the [writing a feature guide](https://fleetdm.com/handbook/engineering#write-a-feature-guide) process to publish an article announcing Fleet same-day support for the new major release.
 
 
 ## Rituals