Kubernetes app: model the new talos.reconcileJobMemoryLimit field (upstream cozystack#3521) #19

Context

cozystack/cozystack PR #3521 adds a new optional field to the
Kubernetes app's values:

It raises the memory limit of the chart-internal talos-reconcile Job above the level at which it gets OOMKilled,
and exposes the limit so operators with a larger management API surface can raise it further.

Why this repository is affected

Per the upstream trigger map (docs/agents/contributing.md, "Downstream Repositories"), this provider is
hand-written: every Kind carries a hand-maintained Terraform schema with its own expand/flatten pair, with no
codegen from values.schema.json. Two entries of that map apply here:

• "Add, remove or rename a field in an app's values.schema.json → the schema, the model, and the expand/flatten
  pair."
• "Change a default in an app's values.yaml → the provider restates the defaults of every field it models […]
  the provider sends its own default rather than letting the API apply yours, so a stale one does not merely
  show up as a diff: it silently wins, and users keep getting the old value."

The second one is the reason this is worth filing rather than leaving to drift: once the field exists upstream, a
provider that models talos but not this attribute is fine, but a provider that later models it with a stale
default would silently pin users to the old value.

What is needed

Add reconcile_job_memory_limit (or the naming this provider uses for nested talos.* attributes) to the
Kubernetes resource schema and its expand/flatten pair, Optional + Computed, default 512Mi, typed as the
provider types other quantity fields.

Not done here

I am reporting this rather than sending a PR: I do not know this provider's conventions for nested optional
attributes or its quantity handling, and getting the Optional+Computed+Default combination wrong is exactly
the failure mode described above. Happy to follow up with a PR if a maintainer confirms the intended shape.

Filed as the downstream follow-up required by the upstream PR checklist.