fix(mysql): fail close ORC prechecks within action budgets

[weicao]

Problem

Two ORC lifecycle paths can report success without trustworthy evidence or exceed the kbagent action window:

1. The switchover master precheck merges orchestrator-client retry stderr into stdout. A transient curl/jq error can become the parsed master token and make the script exit 0 as "not the master" without attempting switchover.
2. memberLeave runs three unbounded orchestrator-client calls. A hung client can be killed by the 60s clamp mid-action, and the old instance ... || true verification cannot distinguish a genuinely absent instance from a failed query.

Change

M1: fail closed on noisy master prechecks

• preserve stdout/stderr separately in the timeout fallback
• extract only the last non-empty host:port token from stdout
• use the same resolver in the initial master guard and post-switchover candidate discovery
• retain raw stdout/stderr/rc diagnostics when resolution fails

M2: bound memberLeave and prove absence

• bound each orchestrator-client call to 10s with a 1s kill grace
• set memberLeave action timeout to 50s; worst case is 3 x 11s + 3s settle = 36s, leaving 14s for diagnostics
• fail rc=1 on forget, reachability, or verification timeout/error
• replace ambiguous instance ... || true with a successful bounded all-instances read and exact hostname absence check
• emit per-action phase and retry-safe diagnostics to action stderr and /tmp/member-leave.log

Tests

• M1: retry stderr + final successful stdout; stderr-only noise; last valid stdout token
• M2: positive absent closure; forget timeout; reachability timeout; list verification timeout; instance still present; missing leaving-member identity

Local gates:

• MySQL ShellSpec: 46 examples, 0 failures (bash 3.2.57)
• focused M1+M2 ShellSpec: 19 examples, 0 failures
• bash-n: PASS
• shellcheck --severity=warning: PASS
• helm dependency build addons/mysql: PASS
• helm lint addons/mysql: PASS
• render: memberLeave timeoutSeconds=50, client timeout 10, settle 3, stderr mirrored
• git diff --check: PASS
• merge-tree: PASS, tree 6d86e28f3cb01fd7ca23f7f13251d6ae59aa6afd

Boundary

This PR is a draft child of #3117 and changes only M1/M2. It does not include PITR cleanup, ORC client/init/preTerminate, M3, or M4 work owned elsewhere. Evidence is code/static only; runtime N=0 and no acceptance or release-readiness claim is made.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 0% with 100 lines in your changes missing coverage. Please review.
✅ Project coverage is 0.00%. Comparing base (2957aa3) to head (0bee076).

Files with missing lines	Patch %	Lines
...ons/mysql/scripts-ut-spec/orc_member_leave_spec.sh	0.00%	70 Missing ⚠️
...ddons/mysql/scripts-ut-spec/orc_switchover_spec.sh	0.00%	30 Missing ⚠️

Additional details and impacted files

@@                        Coverage Diff                         @@
##           henry/task82-orc-roleprobe-budget   #3158    +/-   ##
==================================================================
  Coverage                               0.00%   0.00%            
==================================================================
  Files                                    147     148     +1     
  Lines                                  23327   23427   +100     
==================================================================
- Misses                                 23327   23427   +100     

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[weicao]

Review-fix update, exact head 0bee07600bf02bf4a4c661216289a147ce117016:

• tightened master token from broad ^[^[:space:]]+:[0-9]+$ to the current Kubernetes-hostname contract ^[^[:space:]:]+:[0-9]+$
• jq:error:42 alone now fails resolution with an empty master
• jq:error:42, valid mysql-current:3306, and trailing curl:error:7 resolves only the valid hostname token

Re-run gates:

• focused M1+M2 ShellSpec: 20 examples, 0 failures
• full MySQL ShellSpec: 47 examples, 0 failures
• bash-n / shellcheck warning gate / helm lint / render / diff-check: PASS
• merge-tree: PASS, tree e692180f286a143ddcb2d23085f69c2cc3c34d48

PR remains draft; runtime N=0.

[weicao]

Closing this PR because its base is henry/task82-orc-roleprobe-budget, not main or a release branch. Per repository PR policy, stacked/integration branches are for local composition only and must not be used as formal PR bases. The commits remain preserved on the head branch; any still-needed change will be re-created from an allowed main/release baseline with the correct scope and evidence.