Add pristine dotnet new webapi scaffold

Baseline commit of the untouched template so the M0 restructure lands as a
reviewable diff rather than appearing as the initial state.

Includes .gitignore and .gitattributes only; no source changes.

.gitattributes

@@ -0,0 +1,50 @@
+# Normalise line endings: LF in the repo, native on checkout.
+* text=auto
+
+# Source
+*.cs        text diff=csharp
+*.csproj    text
+*.slnx      text
+*.props     text
+*.targets   text
+*.json      text
+*.axaml     text
+*.xaml      text
+*.ts        text
+*.js        text
+*.css       text
+*.html      text
+*.md        text
+*.yml       text
+*.yaml      text
+*.sql       text
+
+# Files that must keep LF regardless of platform — shell scripts run in Linux
+# containers, and Dockerfiles are read by a Linux daemon.
+*.sh          text eol=lf
+Dockerfile    text eol=lf
+*.Dockerfile  text eol=lf
+Caddyfile     text eol=lf
+
+# Windows-only scripts keep CRLF
+*.cmd text eol=crlf
+*.bat text eol=crlf
+*.ps1 text eol=crlf
+
+# Binary — never diff or convert
+*.png  binary
+*.jpg  binary
+*.ico  binary
+*.icns binary
+*.gif  binary
+*.pdf  binary
+*.zip  binary
+*.gz   binary
+*.dll  binary
+*.so   binary
+*.dylib binary
+*.pfx  binary
+*.snk  binary
+
+# Test fixtures are byte-exact contracts — never touch their line endings.
+tests/fixtures/**  -text