Refactor: quickfiler-uncompiled-viewer-orphans-and-legacy-trees

[drmoisan]

• Work Mode: minor-audit

Problem / Why

Uncompiled files in the source tree are actively misleading: they are read by humans and by agents as if they were live code, they surface in greps and symbol searches, and they can carry latent traps that appear to be real defects. Feature #464 deleted three such orphans (EfcViewer3.cs, EfcViewer3.Designer.cs, EfcViewer3.resx) and confirmed their removal required no project-file edit at all, which is precisely what proves they were dead. The remaining orphans have the same status.

Implementation Intent

Remove the seventeen remaining QuickFiler/Viewers/*.cs files that carry no Compile Include entry, together with the QuickFiler/Legacy/** and QuickFiler/Notes/** trees. This is repository hygiene, not a behavior change: no compiled code references any of them.

Acceptance Criteria

• Each deleted file is proven to have had no Compile Include entry in any .csproj before deletion.
• QuickFiler/QuickFiler.csproj has a zero-line diff, as it did for Bug: efc-controllers-null-guard-and-async-void-boundary-defects #464's EfcViewer3 deletions.
• The full toolchain passes with no new analyzer or nullable diagnostics and no change in test count.
• A repository-wide search shows no surviving source reference to any deleted type.

Dependencies / Risks

Low risk, but the enumeration must be verified rather than assumed: a file can be referenced by a .resx, a designer partial, or a wildcard glob rather than an explicit Compile Include. Verify each file individually before deleting. Coordinate with any live sibling feature that owns a Viewers\* project-file region.

Verification Steps

• Full QuickFiler.Test run before and after, with an identical pass count
• Analyzer and nullable builds with /t:Rebuild, proving non-vacuity via zero Skipping target "CoreCompile" lines
• Repository-wide grep for each deleted type name returning zero hits

Evidence Checklist

• Baseline
• End-state
• Targeted verification

Source

From: docs/features/potential/2026-08-27-quickfiler-uncompiled-viewer-orphans-and-legacy-trees.md