PMM-15076 Fix NUMA Details dashboard to show all NUMA nodes by default

[ondrejpatocka]

Problem

• node variable shipped as single-value, hidden, defaulting to 0 - so per-node rows
  ("repeat": "node") only rendered for Node 0 on multi-NUMA hosts.
• Contradicts the user manual: "For each node, this dashboard shows metrics…".

Changes (dashboards/OS/NUMA_Details.json)

• node variable → multi: true, includeAll: true, hide: 0, default $__all
  (now consistent with the sibling zone variable).
• 26 panel queries: node="$node" → node=~"$node" to match the regex substitution
  produced by a multi-value variable.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 43.05%. Comparing base (d635fc3) to head (28967d4).

Additional details and impacted files

@@            Coverage Diff             @@
##               v3    #5389      +/-   ##
==========================================
- Coverage   43.20%   43.05%   -0.15%     
==========================================
  Files         413      543     +130     
  Lines       42302    44650    +2348     
  Branches        0      590     +590     
==========================================
+ Hits        18278    19226     +948     
- Misses      22157    23548    +1391     
- Partials     1867     1876       +9     

Flag	Coverage Δ
admin	34.94% <ø> (ø)
agent	48.95% <ø> (-0.20%)	⬇️
unittests	41.31% <ø> (?)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.