Match PerformanceStudio's runtime summary card: title, order, memory-grant colors, spill flag

[erikdarlingdata]

Fixes #4570. Part of #4511. The CPU:Elapsed row came with #4565.

Why

PerformanceStudio's Avalonia plan viewer (erikdarlingdata/PerformanceStudio@40ade29, superseding @5731ae9) changed its runtime summary card in four ways the shared PM/Lite viewer didn't have: the card's title becomes "Predicted Runtime" for a statement with no runtime stats (estimated-plan-only); the memory grant row is colored by utilization, with an over-used grant (>100%) always red and any spilled operator anywhere in the plan forcing at least the warning tier plus a "⚠ spill" suffix; the efficiency thresholds used for memory grant / DOP / thread utilization loosened from the old ≥80/≥60/≥40 tiers to ≥40 (default) / ≥20 (warning) / <20 (error); and the row order changed to Elapsed → CPU:Elapsed → DOP → CPU → Compile → Memory grant → Optimization → CE model.

What changes

• PerformanceMonitor.PlanAnalysis/PlanDisplayText.cs: five new pure, pinned helpers plus a RuntimeSummaryRow record:
  • RuntimeSummaryTitle(statement) — "Predicted Runtime" vs "Runtime Summary".
  • HasSpillInPlanTree(node) — recursive walk for any warning type ending in " Spill".
  • EfficiencyColorKey(pct) — the ≥40/≥20/<20 tiers (used for DOP and thread efficiency; null means the card's default value color).
  • MemoryGrantColorKey(pctUsed, hasSpill) — >100% is always the error tier; a plan-wide spill forces at least the warning tier; otherwise follows EfficiencyColorKey.
  • BuildRuntimeSummaryRows(statement): the whole card's row list in PerformanceStudio's order, as a pure function a test can call directly. PerformanceStudio's desktop viewer builds its runtime summary rows directly, with no equivalent extra-rows parameter, and so does this.
• PerformanceMonitor.Ui/PlanViewerControl.Properties.cs: ShowRuntimeSummary now sets the title from PlanDisplayText.RuntimeSummaryTitle and builds its rows entirely from PlanDisplayText.BuildRuntimeSummaryRows, applying each row's ColorKey as a theme brush resource lookup (ErrorBrush/WarningBrush/default). The old inline FormatMemoryGrantKB moved into the shared helper (used internally by BuildRuntimeSummaryRows); the WPF file no longer needs its own copy.
• PerformanceMonitor.Ui/PlanViewerControl.xaml: the static "Runtime Summary" TextBlock gets x:Name="RuntimeSummaryTitle" so the code-behind can swap its text.

Lite: gets this too (shared control — PlanViewerControl is hosted by both the Darling Viewer and Lite; no Lite-specific code changed).

PM-ahead: none noted for this card.

Test plan

New pins: Darling/Darling.Tests/Viewer4570Tests.cs, 22 facts/theories covering the title swap, the spill-tree walk (null root, no warnings, non-spill warning, root warning, warning deep in a child), the efficiency threshold boundaries (100/40/39.9/20/19.9/0), the memory-grant color combinations (over-used with/without spill, high utilization with/without spill, low utilization), the actual-plan row order, the estimated-plan row omissions, the memory-grant row's color/spill-tag, and compile time always showing.

RED on the base branch (plan-sync/4537-drop-rules @ a38f81d): all five helpers plus RuntimeSummaryRow are new, so the test file fails to compile there (CS0117/CS0246 on every reference) — a labelled compile-only RED, since every helper is new.

Mutation (runtime RED, not just compile-fail): changed EfficiencyColorKey's thresholds from pct >= 40 ... pct >= 20 to pct >= 80 ... pct >= 60. Result: 4 of 23 facts failed (MemoryGrantColorKey_HighUtilizationNoSpill_IsDefault, and the three EfficiencyColorKey_MatchesPsThresholds boundary cases at 40/39.9/20). Reverted; rebuilt; all 23 pass again (Total: 23, Errors: 0, Failed: 0).

Full run (built Darling.Tests, PerformanceMonitor.Ui, Lite/PerformanceMonitorLite.csproj, Darling/PerformanceMonitor.Darling.Viewer Release with -p:EnableWindowsTargeting=true, all 0 warnings/0 errors): Viewer4570Tests plus every required Viewer*/PlanSync*/plan-analysis pipeline class → Total: 253, Errors: 0, Failed: 0, Skipped: 1, Not Run: 0. (The one skip is DarlingMcpPlanToolsLivePostgresTests, which needs a live Postgres rig not available here; unrelated to this change.)

Lite.Tests and Lite/PerformanceMonitorLite.csproj: build-only on this machine (net10.0-windows can't execute Lite.Tests here); no Lite-specific code changed by this PR, so no new Lite pin is needed — CI decides the Windows-only run.

Screenshot plan: open any actual plan with a memory grant in the Darling Viewer or Lite. Expect: card titled "Runtime Summary"; rows in order Elapsed, CPU:Elapsed, DOP, CPU, Compile, Memory grant, Optimization, CE model (only the ones the plan has data for); the Memory grant row's value colored red if used% > 100, orange (warning) if any operator spilled or utilization is 20-39%, default color otherwise, with "⚠ spill" appended when any operator spilled. Open an estimated-only plan (no runtime stats): the same card's title reads "Predicted Runtime".

CHANGELOG

SECTION: Changed
ENTRY: - The plan viewer's runtime summary card matches PerformanceStudio's ([#4590]) - It's titled "Predicted Runtime" for an estimated-only plan, rows are reordered (Elapsed, CPU:Elapsed, DOP, CPU, Compile, Memory grant, Optimization, CE model), the memory grant row is colored by utilization (red over 100% used, orange when any operator spilled or utilization is moderate-low, red when utilization is very low) with a "⚠ spill" tag when any operator in the plan spilled, and compile time is always shown.
REF: [#4590]: #4590