WA-NEW-010: Eliminate BSON Symbol deprecation warning in test suite

[kitcommerce]

Summary

Resolves #627.

mongoid-audit_log (v0.6.1) declares field :action, :type => Symbol in its Entry model. Mongoid 7.4.x emits a one-time warning — The BSON symbol type is deprecated; use String instead — whenever a field is registered with the Ruby Symbol type. This warning appears on every test boot, polluting CI/CD output and making it harder to spot real issues.

Root cause: BSON 5.x deprecated the BSON Symbol wire type (0x0E). The warning is Mongoid's notice that using it will break in a future BSON version.

Fix — two parts:

1. core/lib/workarea/ext/freedom_patches/mongoid_audit_log.rb (new)
   Pre-sets Mongoid's one-time-warned flag before require 'mongoid/audit_log' so the gem's own field definition cannot trigger the warning. The inline comment explains why this suppression is safe and correctly scoped.

2. core/lib/workarea/ext/mongoid/audit_log_entry.rb (modified)
   In our existing decorate Entry block, re-declares action as type: String, overwrite: true — the actual underlying fix. A custom #action reader wraps super&.to_sym so the attribute still returns a Symbol, preserving the public contract (the gem's own create? / update? / destroy? predicates compare against symbol literals and continue to work unchanged).

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Test command output

Before this PR:

W, [...] WARN -- : The BSON symbol type is deprecated; use String instead
...
4 runs, 31 assertions, 0 failures, 0 errors, 0 skips

After this PR:

$ bundle exec ruby -Icore/test core/test/lib/workarea/configuration/administrable/fieldset_test.rb
2026-02-20T07:31:58.729Z pid=13192 tid=8jw INFO: Sidekiq 7.3.10 connecting to Redis...
Run options: --seed 7444

# Running:

....

Finished in 0.200761s, 19.9242 runs/s, 154.4125 assertions/s.
4 runs, 31 assertions, 0 failures, 0 errors, 0 skips

No BSON symbol warning. ✓

Also verified (no regressions):

• core/test/lib/workarea/ext/mongoid/audit_log_entry_test.rb → 3 runs, 9 assertions, 0 failures
• core/test/middleware/workarea/audit_log_middleware_test.rb → 1 run, 2 assertions, 0 failures

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Client impact

None expected for most implementations.

The action attribute on Mongoid::AuditLog::Entry still returns a Ruby Symbol (e.g. :create), so any code comparing or switching on that value is unaffected.

Data migration note: Not required for correctness. Existing documents with the deprecated BSON Symbol type (0x0E) are read back transparently — the BSON driver decodes them as Ruby Symbol; Mongoid's String demongoizer converts to String; the #action reader calls .to_sym. New documents will store "create" (UTF-8 String, BSON type 0x02) going forward. A background migration to normalise old documents can be applied separately if desired; it is not a prerequisite for upgrading.

[kitcommerce]

Dispatcher Build Gate Summary (local)

• rubocop (diff-only): PASS (0 offenses)
• brakeman: skipped (per repo build gate config; disabled)
• tests (affected engines): PASS
  • core: PASS

Observation: core test output no longer prints the BSON Symbol deprecation warning on this branch (expected).