Keep Personal quality checks on concrete preset qualities

[Jellman86]

Outcome

Personal quality checks now compare each video preset at its concrete configured
quality without recursively running Adaptive per-title VMAF inside every
12-second scene.

Normal optimisation jobs retain Adaptive per-title VMAF. Preview jobs also
retain it so a requested Preview can still reflect the library's selected
quality path.

Root cause

The dispatcher started adaptive quality selection for every video re-encode
whose library used AdaptiveVmaf. Calibration jobs are deliberately associated
with their library so they can resolve each complete preset, which unintentionally
made every one of their planned scene jobs eligible for another
early/middle/late adaptive search.

For an 8-bit video check, 4 presets × 3 scenes × up to 4 qualities × 3 adaptive
windows could prepare as many as 144 redundant 40-second encode-and-score
passes before producing the intended clips.

What changed

• calibration jobs are excluded from adaptive quality selection
• each anonymous preset keeps one concrete quality across its three scenes
• completed video scenes still receive structural verification and measure-only
  VMAF evidence
• normal and Preview adaptive behaviour remains unchanged
• user, API, architecture, and roadmap documentation now state the boundary

Safety

Calibration remains disposable and replacement-ineligible. This change removes
preparation work; it does not weaken structural verification, alter normal-job
VMAF gates, or permit any source mutation.

Validation

• regression test failed before the fix and passes after it
• dotnet build Optimisarr.slnx --configuration Release --warnaserror
  — zero warnings
• dotnet test Optimisarr.slnx --configuration Release --no-build
  — 1,489 passed
• OpenAPI, release-metadata, documentation-link, and diff checks passed
• live read-only diagnosis confirmed that one old calibration session had
  entered the nested adaptive search while its session progress remained near 4%