Follow-up to #95: untrack .res and Together modelling leftovers

[omonien]

For Markus — follow-up to #95

In #95 we agreed that:

1. .res can stay ignored (IDE regenerates from .dproj)
2. Modelling leftovers (*.txaPackage / *.txvpck) can be ignored now that modelling is gone

.gitignore only stops new noise. Files that were already tracked stayed in the tree. This PR removes them from the repo.

What I checked (.res)

Every tracked .res is a normal Delphi project resource linked with {$R *.res} / {$R *.RES} — none is an external/hand-maintained resource:

Kind	Finding
Links	Only {$R *.res} in .dpr files — no {$R SomeCustom.res}
.rc files	None in the repo
Icons	Source icons stay tracked (Hash.ico etc.); dproj references them as MainIcon
VersionInfo	Comes from the .dproj and is regenerated into .res by the IDE/build
Size	Console stubs (~96 bytes) or icon+VersionInfo blobs (~150 KB) — both regenerable

Conclusion: safe to untrack all of them. After clone, the IDE (or first build) recreates .res as needed.

What I removed

Category	Paths
17 × .res	Demos, Install, Source/DEC60, Unit Tests
Together modelling tree	Source/LibrarySupport/ (entire)
Together modelling tree	Unit Tests/ModelSupport_DECDUnitTestSuite/ (entire, incl. Klassendiagramm.txvcls)
Project diagram configs	4 × *_project.tvsconfig / *_prjgroup.tvsconfig

.gitignore extension

Already had *.res, *.txaPackage, *.txvpck. Added:

• *.tvsconfig
• *.txvcls
• Source/LibrarySupport/
• Unit Tests/ModelSupport_*/

Comment updated: no longer says “tracked files stay until cleanup”.

What stays tracked (on purpose)

• Source icon assets (Hash.ico, PNG launch images, …)
• .dfm / .fmx (form resources via {$R *.dfm} / {$R *.fmx})
• All source / dproj / tests

Risk

Very low — no source or build logic change. First IDE open of a demo/test project may recreate a local .res (ignored, not committed).

Test plan

• Confirm no wanted file disappeared from the tree (icons/dproj/source intact)
• Optional: open one demo in the IDE and build — .res is recreated locally
• Optional: run unit test suite once

Happy to split .res vs modelling if you prefer two reviews; kept as one follow-up because both were the open end of #95.