Do not skip explicitly configured integer zero in config - #6867

## Release v1.19.0

### CLI

 * Honor `CLAUDE_CONFIG_DIR` in `aitools` commands. ([#6838](#6838))
 * Added `--ttl` and `--no-expiry` flags to `databricks postgres create-branch` so a branch's expiration can be set without hand-writing a `--json` spec. `--ttl` accepts the REST API duration form (`604800s`), a Go duration (`168h`), or day/week units (`7d`, `3w`); `--no-expiry` creates a branch that never expires. One of `--ttl`, `--no-expiry`, or a spec expiration in `--json` is required. ([#6313](#6313))
 * `databricks ssh connect` serverless sessions now provide Claude Code and Codex configured with Unity Gateway out of the box. ([#6885](#6885))

### AI Runtime

 * Add `databricks air images push` (Preview) to configure Docker authentication and push container images to Databricks Artifact Registry. ([#6869](#6869))
 * `air run` now grants the configured `permissions` on the MLflow experiment as well as the job. ([#6870](#6870))

### Bundles

 * Add libraries field to clusters. ([#6831](#6831))
 * Error out when a configured `workspace_id` does not match the connected workspace, instead of silently using it in resource URLs emitted by `bundle summary`. ([#6754](#6754))
 * Fix spurious recreation of Lakebase (Postgres) branches, roles, and catalogs when the referenced project is updated in place: an in-place project change (e.g. `display_name`) no longer forces a delete + create of resources that reference the project's or branch's `name`. ([#6865](#6865))
 * Direct engine now detects and applies an explicitly configured integer zero (e.g. `gcp_attributes.local_ssd_count: 0`) added to a resource first deployed without the field. ([#6867](#6867))
 * Migrate existing Terraform deployment state to the direct engine before deploying (previously done after a Terraform deploy), so the deploy runs on the direct engine. ([#6749](#6749))
 * The `postgres_snapshot_schedules` resource (introduced in [v1.16.0](https://github.com/databricks/cli/releases/tag/v1.16.0)) is now marked Beta and is no longer available in PyDABs, matching the other `postgres_*` resources; configure it in YAML instead. ([#6887](#6887))

Generalize the direct-engine zero-value change detection from #6867 so an
explicitly configured false or 0.0 (e.g. gcp_attributes.use_preemptible_executors,
azure_attributes.spot_bid_max_price) is applied the same way an explicit integer
zero already is. Strings stay excluded on purpose, since backends routinely
normalize "" to null and back.

Renames isZeroInt to isZeroScalar (now covering ints, floats and bools) and adds
bool/float cases to TestScalarZeroChange plus end-to-end acceptance tests mirroring
local_ssd_count_update.

Co-authored-by: Isaac <no-reply@databricks.com>

The integer entry from #6867 has shipped, so this change needs its own entry.

Co-authored-by: Isaac <no-reply@databricks.com>

…ger (databricks#6882)

Generalizes the direct-engine zero-value change detection from databricks#6867
from integers to all numeric and boolean scalars.

An explicitly configured `false` or `0.0` (e.g.
`gcp_attributes.use_preemptible_executors: false`,
`azure_attributes.spot_bid_max_price: 0`) added to a resource first
deployed without the field is now detected and applied, exactly as an
explicit integer zero already is. `isZeroInt` becomes `isZeroScalar`
(ints, floats, bools).

Strings are left out to stay in line with the `DropEmptyStrings`
mutator, which drops an explicit `""` before the plan runs.

Adds bool/float cases to `TestScalarZeroChange` (plus an empty-string
no-op case) and two end-to-end acceptance tests
(`use_preemptible_update`, `spot_bid_max_price_update`) mirroring
`local_ssd_count_update`.

This pull request and its description were written by Isaac.

---------

Co-authored-by: Isaac <no-reply@databricks.com>