enhance(gh): 複数サンプルの値の表示を改善するなど (#17759)

* docs: design backend diagnostics memory noise handling

* chore(gh): tweak workflow

* docs: clarify shared heap snapshot reporting

* docs: plan backend diagnostics memory noise handling

* chore: ignore local worktrees

* feat(diagnostics): add independent delta summary

* feat(diagnostics): make heap snapshot deltas noise-aware

* docs: correct heap snapshot threshold plan

* fix(diagnostics): suppress backend memory noise

* ci: refine backend diagnostics sampling

* test(diagnostics): address final review

* wip

* Update heap-snapshot-sampling.ts

* wip

* wip

* docs: design frontend metric noise reporting

* docs: plan frontend metric noise reporting

* fix(diagnostics): suppress frontend metric noise

* docs: remove temporary frontend metric plans

* test(diagnostics): cover frontend metric thresholds

* docs: design shared diagnostics metric table

* docs: plan shared diagnostics metric table

* refactor(diagnostics): simplify independent delta statistics

* feat(diagnostics): add shared metric table renderer

* refactor(diagnostics): use shared heap snapshot table

* refactor(diagnostics): use shared backend metric table

* refactor(diagnostics): use shared frontend metric table

* docs: remove temporary metric table plans

* tweak

* docs: design metric table no-data output

* fix(diagnostics): show marker for empty metric tables

* chore: remove temporary diagnostics design

.github/workflows/backend-diagnostics.inspect.yml

@@ -89,9 +89,10 @@ jobs:
     - name: Measure backend memory usage
       working-directory: head
       env:
-        MK_MEMORY_COMPARE_ROUNDS: 10
+        MK_MEMORY_COMPARE_ROUNDS: 15
         MK_MEMORY_COMPARE_WARMUP_ROUNDS: 1
         MK_MEMORY_HEAP_SNAPSHOT: 1
+        MK_MEMORY_HEAP_SNAPSHOT_ROUNDS: 3
         # 計測ハーネスはhead側のものを両方に使うが、成果物はrunnerのworkspace直下に出す
         MK_MEMORY_HEAP_SNAPSHOT_OUTPUT_DIR: ${{ github.workspace }}
       run: >-