fix(security): validate the Db2 certificate fetch and contain its local-path branch (#14637)

* fix(security): validate the Db2 certificate fetch and contain its local-path branch

The IBM Db2 Vector Store and watsonx.data Presto components accept a
tenant-controlled certificate location (``ssl_certificate_path`` /
``ssl_ca_file``). Both resolve it through
``db2_security.validate_and_prepare_ssl_certificate``, which had two
unguarded branches:

- the URL branch downloaded through a raw urllib client with no
  internal-host policy applied, and followed redirects silently, so a
  first-hop-only validator would not have helped either;
- the local-path branch resolved any absolute/relative path with no
  containment.

Route the download through the existing shared guard
``lfx.utils.ssrf_httpx.ssrf_safe_httpx_get``, which validates the host
against the connector SSRF policy, pins the connection to the validated
IPs, and re-validates every redirect hop rather than only the first.
Reject non-http(s) schemes instead of letting them fall through to the
local-path branch, and hold the local path inside the caller's storage
scope via ``enforce_local_file_access`` (a no-op unless
``LANGFLOW_RESTRICT_LOCAL_FILE_ACCESS`` is enabled, so the OSS default
is unchanged). Cap the buffered response size.

No shared code changed -- the fix consumes the existing guards. Both
component call sites now pass ``component_file_access_scopes(self)``.

Regression coverage in src/bundles/ibm/tests/test_db2_security.py:
internal/metadata/RFC1918 targets are refused, an allowed first hop
cannot smuggle an internal target via redirect, non-http(s) schemes are
rejected, local paths are contained to the caller's scope while
in-scope and unrestricted-default reads keep working, and a static
check pins the module against regaining a raw urllib network sink.

Fixes LE-2247

* chore(bundles): bump lfx-ibm to 0.2.1 for the changed Db2 certificate path

Generated by scripts/ci/bundle_release_plan.py update --base-ref origin/release-1.12.0.
The release-plan guard requires a version bump whenever releasable bundle source
changes, and this PR modifies src/bundles/ibm.

* fix(ci): realign the enterprise-hardened profile with the lfx-ibm bump

The bundle release-plan guard requires a version bump when releasable bundle
source changes, which moved the root pyproject floor to lfx-ibm>=0.2.1. The
checked-in release contracts still described >=0.2.0, so test_bundle_profiles
went red. Update the reviewed profile and regenerate the lock with
manage_bundle_profiles.py compile rather than editing the lock by hand.

* fix(security): bound the certificate download and clean up its temp file

Two issues on the certificate path.

The 1 MiB cap was enforced on an already-buffered body, so an endpoint that
passes SSRF validation could still exhaust memory by answering with an unbounded
response. ssrf_safe_httpx_get_bounded streams instead and abandons the transfer
as soon as the cap is passed, keeping the per-hop redirect revalidation.

The watsonx.data Presto component discarded the is_temp flag from
validate_and_prepare_ssl_certificate, so an https:// CA file leaked one
temporary file per query. _tls_verify now returns ownership and run_query
unlinks it in a finally, covering the failure path where leaks accumulate.
An operator-supplied local path reports is_temp False and is never removed.

Both predate this PR but sit on the certificate path it hardens.