feat(mysql): classify removed 8.4 parameters

[weicao]

Problem

KubeBlocks controller PR #10684 adds an opt-in action result policy for deterministic rejected parameters. MySQL 8.4 already rejects a fixed set of removed variables before SET GLOBAL, but that path currently shares generic exit code 1 with authentication, connection, probe, unknown-variable, and other execution failures. Mapping exit 1 would therefore misclassify infrastructure or engine errors as InvalidParameter.

Change

• return dedicated exit code 64 only when the server version is parseable as MySQL 8.4+ and the normalized parameter is in the fixed eight-member removed-variable list
• map only exit code 64 to InvalidParameter with retry: false in the shared reconfigure action
• retain generic exit code 1 for all other failures
• cite the upstream MySQL removed-features source and require a dedicated test for each list member
• render-test all seven MySQL reconfigure actions and assert no exit-code-1 mapping

This PR is stacked on #3086 (helios/mysql-84-paramsdef) and includes the three commits from #3080 that provide the generic error and removed-variable foundation.

TDD evidence

Before the product patch, the focused suite was 22 examples / 9 failures: all eight removed-variable cases returned 1 instead of 64 and the seven rendered actions had no result mapping.

After the patch:

• focused ShellSpec: 23 examples / 0 failures
• all MySQL ShellSpec: 29 examples / 0 failures
• Bash syntax: PASS
• ShellCheck severity error: PASS
• Helm lint: PASS
• Helm render + structured parse: seven reconfigure actions, each with exactly [{execExitCode: 64, code: InvalidParameter, retry: false}]
• git diff --check: PASS
• isolated implementation review: no blocking finding

Runtime boundary

Runtime is N=0 / NOT_RUN. Acceptance requires controller manager and Pod kbagent sidecar built from the exact same #10684 head, then the focused MySQL 8.4 rejected-parameter rollback and subsequent valid reconfigure checks.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 0% with 177 lines in your changes missing coverage. Please review.
✅ Project coverage is 0.00%. Comparing base (db05fdc) to head (e4b569c).

Files with missing lines	Patch %	Lines
...ons/mysql/scripts-ut-spec/update_parameter_spec.sh	0.00%	161 Missing ⚠️
...pts-ut-spec/update_parameter_result_policy_spec.sh	0.00%	16 Missing ⚠️

Additional details and impacted files

@@                    Coverage Diff                     @@
##           helios/mysql-84-paramsdef   #3224    +/-   ##
==========================================================
  Coverage                       0.00%   0.00%            
==========================================================
  Files                            147     149     +2     
  Lines                          23282   23459   +177     
==========================================================
- Misses                         23282   23459   +177     

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